Mayor Karen Bass of Los Angeles announced that Steve Soboroff, a developer and former police commissioner, will serve as the city’s chief recovery officer — effectively placing him in charge of overseeing the initial rebuilding efforts. This comes on the heels of an executive order the mayor issued earlier in the week, which is aimed at clearing debris and speeding up rebuilding and repairs.

Tens of thousands of people were still under evacuation orders or warnings on Friday as firefighters made progress on the biggest blazes. Authorities have allowed some residents to re-enter their homes inside some evacuation zones — including in the Encino and Brentwood neighborhoods near the Palisades fire — but curfews in those areas are in effect from 6 p.m. to 6 a.m., according to officials.

Benign weather is forecast for L.A., providing some relief for firefighters. With winds coming off the ocean, instead of down the mountains, forecasters believe there’s little potential for new fires through this weekend. But there’s also little rain in the forecast, and vegetation remains parched, creating conditions ripe for wildfires to return next week. Though forecasts are far from certain at this point, the most likely scenario is another surge of Santa Ana winds late Monday into Tuesday.

The fire that razed Melise Gerber’s house raced from the dry slopes of the San Gabriel Mountains above Los Angeles through thousands of tightly packed homes, through a beloved 1950s diner, a sprawling Victorian-style mansion, an entire strip of downtown stores — its damage extending miles from anything locals considered wilderness.

The path of destruction confounds Ms. Gerber, 58, a Southern California native who for a quarter-century lived in her brick-red bungalow in Altadena, a historic town 15 miles northeast of downtown L.A. Firefighters had always been able to quickly contain fires to the foothills above the city, she said.

“My house had been there almost 80 years, and nothing had ever happened,” said Ms. Gerber, who works in marketing. “I just don’t understand it.”

The devastation from the two major fires that erupted in L.A. last week has stunned Californians, with more than 10,000 structures across the region destroyed and at least 27 people killed. The damage, fueled by once-in-a-decade wind gusts and an extremely parched landscape, has reached much farther into cities than many residents thought possible.

The destructive power of the infernos multiplied when they entered neighborhoods, fire scientists say: They transformed into urban fires, in which homes ignited one after the other — and little could be done to slow the spread.

“The houses became the fuel,” said David Acuña, spokesman for Cal Fire, the state’s fire agency. “It’s a structure fire within a wildland fire, which is bad. But then you multiply that by five or 10 structure fires, all at the same time, all being pushed by 100-mile-per-hour wind. It’s what people keep saying: It’s what appears to be Armageddon.”

“The devastation is so unbelievable. Even as a victim of it, it’s hard to comprehend.”

Melise Gerber, who lost her home in the Eaton fire.

The morphing of wildfires into urban fires has created some of the worst disasters in the nation’s history. During fires in Paradise, Calif., in 2018 and another in Maui in 2023, homes emitted heat and embers that set other homes ablaze. In 2017, a wind-whipped fire in California’s wine country destroyed more than a thousand homes in a suburban development long considered invulnerable to wildfire, 10 miles from the rural area where the blaze had begun.

“Once the fire is inside the city, it doesn’t need the wildland to spread anymore,” said Albert Simeoni, a professor and the head of the fire protection engineering department at Worcester Polytechnic Institute in Massachusetts.

The fuel for these urban fires often comes from houses that were constructed long before California enacted strict building codes aimed at preventing fires and were not retrofitted. That means, experts say, that the risks could be controlled, in part, with improved building codes and safety practices. If homes are less vulnerable to catching fire, the blazes cannot sustain themselves with fuel from other homes once they leave the wilderness.

“I don’t know that we’ll mitigate every potential loss, but I think we can substantially change the outcome,” said Yana Valachovic, a fire scientist with the University of California, as she surveyed damage in the L.A. fires this week. “There are things that people can do.”

Proximity to wilderness has long been an attraction of the West, especially in Los Angeles, where the city’s 19th-century boosters sold a vision of suburban communities nestled in nature — an alternative to the crowded, dense cities of the East Coast. William Deverell, a professor of American history at the University of Southern California, said the region was cheerfully marketed as having “an unusually harmonious relationship with nature,” where one could go surfing and skiing in the same day, pick oranges off trees and enjoy 75-degree weather in January.

So, what fire scientists now describe as living in “the wildland-urban interface” — developments that bump up against forests and grasslands and are particularly fire-prone — is a generations-old way of life in Southern California. Some of the region’s most iconic and desirable places to live are in such areas, including the Hollywood Hills, Malibu and Calabasas.

For 18 years, Nancy Spiller savored “the magic of living in the canyon” high up in the Pacific Palisades neighborhood of L.A., where the sun each morning would cast the craggy brush-covered mountains outside her window in a spectacular orange glow. Ms. Spiller, 71, watched the fog march in from the Pacific Ocean during her daily trail runs.

Ms. Spiller’s town-home complex, known as the Woodies, was consumed last week as fire stretched from oceanside bluffs near Santa Monica up into the hills where Ms. Spiller lived. Little is left of the dozens of two-story town homes beyond piles of rubble, warped metal fences and several mostly unscathed trees.

In recent years, residents had removed some pine trees from the complex grounds for fear they would “be like Roman candles in case of a fire,” Ms. Spiller said. Now it’s clear that they underestimated the flammability of the homes themselves, built in the early 1970s with wood siding and wooden fences.

“It’s the property that went up like Roman candles,” said Ms. Spiller, a writer and artist.

California’s building code for wildfires is among the most stringent in the nation, requiring homes in high risk areas to follow guidelines aimed at limiting fires, including using materials that are less likely to burn, such as stucco, concrete or steel. Windows must be made of tempered glass, which is less likely to shatter and allow embers inside a home.

The state’s codes were developed after a fire in 1991 tore through thousands of homes in the verdant hills above Oakland, a high-profile example of a wildfire that turned houses into kindling. But the new codes, enacted in 2008, apply only to homes constructed after that year. The code did not require residents to retrofit older homes — a prospect that could be extremely costly for longtime homeowners and landlords — and such retrofits are relatively rare, officials say. So, in general, older homes are more likely to burn.

Altadena, where the Eaton fire has burned nearly 7,200 structures, has one of the oldest stocks of residential housing in the state, with half of all homes built before 1946. Fewer than one in 100 homes in the area that has burned in Altadena were built after the new codes in 2008, a New York Times analysis of property records found.

In the Palisades, the center of the other major L.A. fire, homes were largely built in the 1950s and 1960s. Fewer than five in 100 homes were constructed since the new codes took effect, the analysis found.

On the bluffs of the Palisades, a 20-minute walk from the beach, Elizabeth Schlaff’s family home, built in 1957, was leveled last week. Ms. Schlaff, grew up in the house, constructed with a wood frame and wood eaves, and said that over six decades, the home had never been subject to a fire evacuation order before last week.

Yet nearly every house on her street, and those nearby, burned. Little but a driveway is left of Ms. Schlaff's house, once painted light blue with a covered porch. At another home, lined by the blackened skeletons of hedges, only the bricks of an entryway and a green metal mailbox remained. At another, structural beams precariously leaned over rubble as they framed a view of a glittering Pacific Ocean.

Ms. Schlaff mourned items that she and her husband forgot to grab as they rushed to evacuate: portraits of his mother, who was a starlet in the Golden Age of Hollywood, antique books, a Civil War-era sword, her mother’s ashes. “Everything burned up,” she said.

In the Paradise fire in 2018, the most destructive in state history, the age of homes influenced how likely they were to burn, researchers found. Roughly 44 percent of homes built after 2008 survived, compared with about 12 percent of those built before 1997, one analysis found. Older homes are more likely to be constructed with wood, have less hardy roofs, include more surrounding vegetation and be closer to other homes — all factors that make them more likely to ignite.

“It’s the property that went up like Roman candles.”

Nancy Spiller said of her townhome complex that was destroyed Palisades fire.

Experts say the people who lived in these neighborhoods ought not be blamed for the fires’ spread. The dangers of huge fires, ever more likely in a warming world, have not been effectively communicated to the public, the experts say, nor is it clear to most people what can be done to make their home safer from a blaze. The experts also say that entire communities need to shift to fire resistant standards, not single homes here or there.

Ms. Valachovic said that wildfires have for too long been framed by officials as primarily forest fires, which makes communities like the Palisades less likely to take the risk seriously. “The sad part is history repeats itself, and we’ve seen many fires now that have this transition to urban or semi-urban setting, and we think they’re anomalies and they’re not,” she said.

Steve Kerber, vice president of UL Research Institutes, who led an investigation commissioned by the Hawaii attorney general of the catastrophic Maui fire, put it another way. “In my opinion, no one in California should be surprised by this at all,” Dr. Kerber said. “This is a disaster that is human created.”

Fire scientists say they hope the fires will be a catalyst for major change, with new requirements for retrofitting older houses, prohibiting rebuilding in burned areas or encouraging people and developers to leave areas that are deemed high-risk.

“We have to recognize that the failure in urban planning happened 50 or 80 years ago when we were first laying out the communities on the fringes of L.A.,” said Michael J. Gollner, an associate professor and director of the fire research laboratory at the University of California at Berkeley. “We know how to make the destruction dramatically less.”

But the overhaul required to fireproof communities comes with enormous costs, either for retrofitting or rebuilding fire-vulnerable homes or for land newly deemed too risky to build on — a particularly difficult prospect in a state with a severe housing crisis. These changes also might mean a painful shift in identity for Californians, as preventing wildfires could require constructing homes without vegetation nearby, far from the wilderness that many hold dear.

Ms. Spiller, who lost her town home in the Palisades Highlands, said she wants to rebuild, if she has the chance. Climate change-fueled disasters threaten many communities, she said, and she believes that she can invest in fire-resistant materials that will make her next home safer.

“We don’t know what the possibilities are,” she said. “We don’t know what the expense is. I just don’t know. So it’s a big open question mark.” But, she said, if she could have her way, she would be there “to witness the canyon coming back to life.”

Three years ago, when Kristin Crowley became the first female chief in the history of the Los Angeles Fire Department, she was lauded as a force for stability.

“There is no one better equipped to lead the L.A.F.D. at this moment than Kristin,” the mayor at the time, Eric Garcetti, said of the 22-year veteran of the department. “She’s ready to make history.”

Now, as Los Angeles reels under an extended onslaught of wind-driven wildfire, its fire chief is being buffeted by challenges in and outside her ranks, tension with City Hall and questions about her department’s preparedness. The fires, which are still unfolding on the city’s west side and in the community of Altadena outside the city, have so far leveled nearly 40,000 acres and claimed at least 27 lives.

Last week, complaints about funding for her department boiled over into a public dispute between Mayor Karen Bass and Chief Crowley. This week, veteran fire managers charged that she and her staff should have positioned more engines in advance in high-risk areas like Pacific Palisades, where the fires began on Jan. 7.

At a news conference, she struggled to explain why an outgoing shift of about 1,000 firefighters was not ordered to remain at work last Tuesday as a precaution amid extreme red-flag conditions. “We surged where we could surge,” she said.

A Jan. 13 letter signed by unnamed “retired and active L.A.F.D. chief officers” accused her of a host of management failures and called for her to step down. “A large number of chief officers do not believe you are up to the task,” the five-page letter read in part.

In an email on Thursday, a fire department spokesperson said that the chief was “focused on mitigating the fires” and unable to respond to the letter. The chief has repeatedly emphasized the progress her crews are making.

“Our firefighters are doing an incredible job,” she said in a news briefing on Thursday, as a continuing air and ground assault brought hot spots in Pacific Palisades closer to containment. “As their chief, I’m extremely proud of the work that our people did and continue to do.”

With thousands of evacuees clamoring to return to the remains of their homes and more red-flag wind conditions in the forecast, many civic leaders in Los Angeles have reserved judgment.

“This was a huge natural disaster not any single fire chief could have prevented, whether they had unlimited resources and money,” said Corinne Tapia Babcock, a member of the Los Angeles Fire Commission, which oversees the department and its chief. “You cannot attack a single person for a situation that is this catastrophic.”

Zev Yaroslavsky, a former member of the Los Angeles County Board of Supervisors and City Council, said that “an accounting should and will take place when the smoke clears.”

“But these issues can’t be resolved while the city’s on fire,” he added.

Other civic leaders predicted that, sooner or later, the chief would be held to account.

“She’ll be gone in six months,” said Fernando Guerra, who directs the Center for the Study of Los Angeles at Loyola Marymount University.

Even before the fire, the chief faced strong political challenges, Dr. Guerra said. Her appointment in early 2022 by the prior mayor, Mr. Garcetti, was seen as an attempt to steady the department after years of complaints of harassment and discrimination raised by female L.A.F.D. firefighters.

But it challenged the male-dominated culture of the department, Dr. Guerra noted, as did the election later that year of Ms. Bass as the new mayor. Like other top managers in Los Angeles city government, fire chiefs are mayoral appointees and can be replaced by a new administration. Ms. Bass kept her on.

Even with more than two decades with the department, Chief Crowley was still new in her post — just beginning to develop a base of support — when the Palisades burst into flames last week.

As the fire turned into a catastrophe, critics of Mayor Bass, including Patrick Soon-Shiong, the owner of The Los Angeles Times, and Elon Musk, the owner of X, the social media platform, charged that the fire department had been underfunded. A December memo from Chief Crowley surfaced, in which she warned the fire commission that a $7.9 million cut in firefighter overtime and the elimination of dozens of civilian positions had “severely limited” the department’s ability to respond to large-scale emergencies.

Ms. Bass had approved a budget last June for the fire department’s current fiscal year that was $23 million less than the prior year’s. But a new contract with the firefighters’ union led to raises, and the final fire budget was actually $53 million more than last year’s.

The claims about underfunding sparked a dayslong dispute with the mayor and her allies. By the end of last week, Chief Crowley had doubled down, telling a local Fox News affiliate that she felt the city government had failed the fire department.

Within hours, she and Ms. Bass — facing criticism herself for having been out of the country when the Palisades fire started — disappeared into the mayor’s office for so long that they missed an evening news briefing. Outside the closed doors, the mayor’s staff repeatedly denied an erroneous report from a British news outlet that the chief had been fired.

By Saturday morning, the mayor and the chief were projecting a unified front, though the tension was apparent. “The chief and I are in lock step,” Ms. Bass said. “And if there are differences that we have, we will continue to deal with those in private.”

But criticisms of the chief flared again this week amid reports in The Los Angeles Times that the firefighting force that was on duty when the Palisades fire started could have been much larger. In years past, the department often paid outgoing shifts overtime to stay at work in times of alarming wind forecasts and tinder-dry conditions.

Internal documents reviewed by The New York Times also showed that the department’s plan on the day of the fire called for advance positioning of only nine additional fire trucks — near Hollywood, the Santa Monica Mountains and elsewhere in the San Fernando Valley — but none in Pacific Palisades.

Patrick Butler, a former L.A.F.D. assistant chief who is now chief of the Redondo Beach, Calif., fire department, said that positioning firefighters and equipment near fire zones in significant numbers well in advance during periods of high wildfire danger has long been a key strategy in the department. “It’s unfathomable to me how this happened, except for extreme incompetence and no understanding of fire operations,” he said.

Others said the fire chief should have kept both the incoming and outgoing shifts of firefighters on duty before the fire as a precaution.

“I can’t speak to why she didn’t exercise it, but it’s a known tactic and it would have doubled the work force,” said Rick Crawford, a former L.A.F.D. battalion chief who is now the emergency and crisis management coordinator for the U.S. Capitol. “I’m not saying it would have prevented the fire, or that the fire wouldn’t have gotten out of control. But she lost a strategic advantage by not telling the off-going shift, ‘You shall stay and work.’”

In the letter purportedly signed by current and retired officers in the department, there were complaints that Chief Crowley had also failed to temporarily call back experienced fire commanders who had recently retired.

“While no one is saying that this fire could have been stopped, there is no doubt among all of us that if you had done things right and prepared the L.A.F.D. for an incident of this magnitude, fatalities would have been reduced, and property would have been saved,” they wrote.

Sharon Delugach, a member of the Los Angeles Fire Commission, said that rumors of disgruntlement within the department had been on the radar but had not risen to the commission’s formal attention before the fires broke out.

Some of the criticism, she said, could reflect sentiments of sexism or homophobia — Chief Crowley is the first lesbian to lead the department — or come from those who were unhappy about change.

Whatever the source, Ms. Delugach said, the timing of the latest dissent is not ideal when many outside of the department seem intent on scoring political points.

“I’m sure they do have very legitimate concerns and I’m sure everybody in the department is there for the right reason,” Ms. Delugach said of the internal criticism. “It’s a shame all this dirty laundry is being aired in the moment of fire.”

Ms. Delugach predicted that Chief Crowley’s future would hinge less on internal and external critiques than on her relationship with Ms. Bass.

“It’s whether she and the mayor can work together, that’s the real question,” Ms. Delugach said. “I hope they can.”

Rachel Nostrant, Nicholas Bogel-Burroughs, Kate Selig and Katie Benner contributed reporting.

It was easy to miss. Susan Toler Carr and her husband, Darrell, were picking through the charred remnants of what had been their home when she spotted a speck of turquoise in the blackened debris: a small metal butterfly, untouched, it seemed, by the fire that had torn through their quiet neighborhood at the foot of the San Gabriel Mountains.

Almost nothing was left of their house. But the butterfly was among the signs that cemented their resolve to stay. This was still home.

The thousands who have lost so much in the Los Angeles wildfires will soon wrestle with how to rebuild the lives that perished with their homes. Leave the neighborhood? Leave the city? The decisions will be personal. For the Carrs, the calculus has particularly deep roots.

Their century-old Spanish Colonial Revival home in Altadena, where they have lived for nearly 25 years, was not just a roof over their heads. It was a place where they had raised their only son, Justin, who was an aspiring architect, an accomplished swimmer, a lyrical poet, a winsome tenor and a painting prodigy.

And it was where they continued to feel his presence, years after he had died at the age of 16, from a sudden and rare heart condition.

To his parents, Justin had remained in the bedroom they had maintained since his death in 2013, in the paint colors he had picked out for the house, in his art on the walls, in the poems he put down on paper and in every manner of butterfly that presented itself — a motif that represented his favorite swimming stroke.

Almost everything was now gone, and yet almost everywhere, memories remained.

“I feel like part of my life went up in smoke,” Mrs. Toler Carr said on Saturday as she prepared to walk around the remains of the house, heat still radiating from the wreckage.

In Los Angeles County, a sprawling region that has long lacked a center, the fires have connected neighborhoods that otherwise had little binding them. Altadena, a racially diverse, middle-class community in the inland shadow of Pasadena, and Pacific Palisades, with its ocean breezes, sublime views and tear-downs starting in the millions, had little in common until they were both ravaged by the fires.

Justin Carr might have grown to be another link.

Earlier generations of his family had been part of a wave of Black people who moved from the South to California, where many settled in the Los Angeles area seeking better jobs and a better life. Mr. Carr’s father had grown up alongside Jackie Robinson in Pasadena. Mrs. Toler Carr’s father, Burl Toler, became the N.F.L.’s first Black referee in 1965. When Justin was a year old, his grandmother looked into his calm, inquisitive eyes and observed: “Oooh, this boy has been here before.”

Justin attended Harvard-Westlake, an exclusive private school with a small population of Black students. In a poem that he wrote for a class and that his parents were presented with after he died, Justin wrote that walking down white halls with white walls, “with kinks in my hair and the dark skin I wear,” left him feeling like a fly in a bowl of milk. He made sure to sit in the front row in class, he wrote, because “it’s hard for me to imagine being stationed in the back, just like my mother and father were, where they couldn’t even see that they were lacking opportunity.”

On the daily bus ride to Harvard-Westlake, 20 miles to the west, Justin struck up a friendship with another Black student, a baseball player. After the baseball team attended Justin’s memorial service, which drew close to 2,000 people, his friend pitched a no-hitter that very afternoon. He told a reporter that he had been thinking of Justin when he took the mound. (Last fall, Justin’s old friend, Jack Flaherty, helped pitch the Los Angeles Dodgers to a World Series championship.)

Justin had been at swimming practice when he went into cardiac arrest, prompted by an undiagnosed heart condition. He was rushed to the hospital, but could not be revived.

Days later, his father had a heart attack.

When Mr. Carr’s older brother picked him up at the hospital to take him to the funeral home to make arrangements, he confided that he didn’t want to live. His brother stopped the car and told Mr. Carr that it was his responsibility to carry on his son’s dreams.

“I was just as limp and as numb as I could be,” Mr. Carr said. “I didn’t know what he was talking about for days, but he made me think, as my older brother makes me really dig in my brain.”

Then it came to him.

At Justin’s memorial service, Mr. Carr recalled the first time he had asked his son to say grace. Justin was 4. He asked God to bless his mother, father, grandfather, a seemingly endless list of cousins, aunts, uncles, classmates, neighbors and pets, before finally — supper was getting cold — asking the Lord for one last thing: world peace.

“I thought, Who am I sitting next to?” Mr. Carr said with a laugh. “Gandhi? Martin Luther King? Medgar Evers?”

The moment became the inspiration for the Justin Carr Wants World Peace Foundation, which offers creative art programs and scholarships, heart screenings and cardiac event training, and peace-building workshops. The foundation’s logo is a silhouette of Justin flashing a peace sign, made from a photo taken by his father.

The Carrs have found purpose in the foundation.

Mrs. Toler Carr, a retired civil engineer who helped design theme parks for Disney and Universal Studios, attended a weekly grief group for five years — in Pacific Palisades, of all places — and said writing has been therapeutic. Mr. Carr, who taught photography and metalworking at high schools and community colleges, has found his own peace.

“There are no stages of grief,” he said, explaining that he has gotten better at managing the pain. “When people ask how I am, I say ‘I am.’”

When the Carrs were alerted by neighbors that the flames from the fire in Eaton Canyon were racing toward their neighborhood, they hustled around the house, gathering up what they could and loading it into their S.U.V. They pulled Justin’s artwork from the walls, packed up boxes of his belongings and, in less than an hour, drove off to a friend’s home 15 miles away in Toluca Lake, where they have been staying since.

They returned the next day and saw what they had left behind. The melted filing cabinets that contained Mr. Carr’s three Contax cameras, his Zeiss lenses and the years of negatives — all priceless. “A photo is a presentation of time, a recording of history that’s never going to happen again,” he said, stifling tears. The verdant backyard where they could take in views of the towering mountains had turned to rubble. The neighborhood, where they knew people by the houses they lived in and the cars they drove, was desolate.

“I’d cry a bucket of tears, but I’m all empty,” Mrs. Toler Carr said during a subsequent visit on Saturday.

Over here was the kitchen. Over there was the patch of milkweed, a magnet for butterflies. The brick chimney, with the herringbone pattern that Justin had designed, still stood. So did the driveway gate, crafted by a former student turned metalworker who had surprised the Carrs with the design. Arched across the top were the words Justin Carr Wants World Peace.

“That gate is a symbol of Justin’s strength,” his father said. “Something to lean on for a new beginning.”

It was already dark when Copter 17 got an urgent call to head to Eaton Canyon. A fire had been reported at 6:18 p.m.

Mike Sagely, one of the most experienced pilots with the Los Angeles County Fire Department, peered through night-vision goggles as he raced the helicopter across the San Fernando Valley.

“There’s the glow,” he told Chris Siok, the battalion chief sitting next to him. Mr. Siok was on an iPad, poring over maps of Altadena, the community nearest to the growing fire.

It was the early evening of Tuesday, Jan. 7. Thousands of homes in Altadena and neighboring Pasadena, Calif., that would soon be incinerated were still intact. Sixteen residents who were eventually killed were still alive. Fire pilots like Mr. Sagely still had a chance to make a dent in what would become the second-most destructive wildfire in California history, by dropping thousands of gallons of water before the blaze became unmanageable.

But at 6:36 p.m. — 18 minutes after the first report of the fire — their plan fell apart.

As they approached the inferno, Copter 17 dropped so violently that the two men were yanked up off their seats, restrained only by their seatbelts. Known for their calm under pressure, they both yelped in shock.

Furious swirling winds were cascading over the mountains and tossing Copter 17 up and down, left and right. Mr. Sagely was fighting for control over the aircraft.

“We knew we were in big fricking trouble,” Mr. Sagely said.

When an extreme gust of wind sent the helicopter plunging around 100 feet, an emergency light on the dashboard flashed a warning that the transmission box was out of oil. It wasn’t — the aircraft plummeted so fast the oil had flown out of the pump to the top of the casing. In his 11,300 hours of flight time over 38 years, including countless combat missions for the Army, Mr. Sagely had never seen that happen.

While battling to stay aloft, they became transfixed by the blinding bright-orange wave of fire beneath them. This account of what it was like inside Copter 17 on the night of Jan. 7 is based on interviews with 10 pilots and crew members, as well as a reporter’s ride in the same aircraft through Eaton Canyon a week later.

The Los Angeles County Fire Department is recognized across the country as a pioneer in using aircraft to fight fires. The department was the first county to adapt the military’s Black Hawk helicopter into a firefighting copter known as the Firehawk, which carries a water tank of 1,000 gallons. The department was also the first in the United States to use night-vision equipment to fight fires in the dark.

Yet the pilots who flew that night speak of weather conditions that humbled them, a ferocity of sustained, 90-mile-an-hour winds that overpowered their equipment and brought them to the edge of an airborne catastrophe. It was a night, they say, that underlined the futility of trying to confront an inferno driven by hurricane-force winds.

“This by far is the worst event I’ve been in, in my career — without a doubt,” said Ken Williams, a pilot for the department with 42 years’ experience and 11,000 flying hours. “Mother Nature was in control that night.”

Before he spent much of his life in the air, Mike Sagely was an aspiring Olympian, a Southern California volleyball player who joined the U.S. Olympic team after the 1984 Games in Los Angeles. When he was released from the team, he enlisted in the Army, aced the flight school test and piloted a wide variety of aircraft.

His military career deployed him to Iraq, Bosnia, Kosovo and Afghanistan, and on numerous classified missions in his 17 years as a Special Operations pilot. He flew 2,000 hours of combat missions, nearly all of them at night.

When he joined the Los Angeles County Fire Department in 2009, he established himself as one of the best night-flying firefighting pilots the agency has ever seen.

“He flies helicopters like Jimi Hendrix plays the guitar,” said Ed Walker, a firefighter-paramedic in the department who has sat next to Mr. Sagely on countless calls. “It’s like the copter is a part of him. It’s an extension of his being.”

Los Angeles is one of the more challenging parts of the country for flying helicopters. The heat of the Mojave Desert and the altitudes of the county’s mountain ranges can stress a helicopter’s engines. In the valleys and flatlands, pilots navigate busy skies, a tangled network of electrical wires and the vast sprawl of America’s most populous county.

Flying across the county at night is even riskier. Mr. Sagely, who has flown nearly 3,000 hours using night-vision equipment, perhaps more than any other firefighting pilot in the country, likens it to trying to drive a car while looking through cardboard toilet-paper tubes.

The county fire department handles a variety of emergencies: hoisting drivers to safety when cars veer off canyon embankments or ferrying the injured and the critically ill to hospitals. But two-thirds of the department’s operational flying time is spent fighting fires, said Dennis Blumenthal, the chief of maintenance at the Air Operations Section.

Their headquarters is in the gritty industrial and working-class Los Angeles neighborhood of Pacoima, in the San Fernando Valley. Loudspeakers issue alarms to alert pilots and crews to an emergency. A printer spits out the details of the call, and the pilots and crew rip the assignment from the printer and head to the helicopters parked on the tarmac.

January and February are normally the calmest months for the Air Operations Section, a time when winter rains have dampened the risk of fire. But this year, the heavy rains never came and the fire risk remained high.

That disrupted the rhythms of the department’s maintenance schedule, the frequent overhauls the aging helicopters require from the repeated stress of loading and dumping. The water alone in the Firehawk’s 1,000-gallon tank weighs more than 8,000 pounds, the equivalent of lifting two average-sized cars.

“No one in the world flies helicopters as hard as we do,” Mr. Blumenthal said. “We are stressing these machines on a continuous basis.”

At 8:30 a.m. on Tuesday, Jan. 7, pilots and crew members gathered in the Air Operations conference room for their daily briefing.

They were advised on what the National Weather Service had been saying for days: The winds would be severe. The Weather Service had issued a rare bulletin of a “Particularly Dangerous Situation,” a warning the federal government issues only about two dozen times a year.

Accustomed to flying in the gullies and canyons of Los Angeles County, the pilots understood what this meant. Strong winds interact with the topography in dangerous ways, flowing down into ravines like the rushing waters of a mountain stream after heavy rains. Just like whitewater, winds can swirl like a whirlpool or crash down on top of an aircraft like a waterfall.

When the first major fire broke out on Tuesday on a ridge high above Pacific Palisades, the lead department was the Los Angeles Fire Department — the city’s firefighting agency — which has its own fleet of helicopters. In the confusing patchwork of Los Angeles County jurisdictions, Pacific Palisades is served by the city, not the county, fire department. “It’s not our dirt,” said Mr. Siok, the battalion chief. As part of its mutual-assistance pact, the county sent two helicopters and a “Super Scooper,” a plane that skims the ocean, sucks up water and dumps it on fires.

At around 6 p.m., Mr. Siok and Mr. Sagely received a call that a fire had started in Malibu. They climbed into Copter 17, a 33-year-old Bell 412 that has flown more than 9,500 hours for the department. The Bell 412 is a descendant of the Huey, the helicopter made famous for its ubiquity during the Vietnam War. Mr. Sagely has a fondness for Copter 17, despite its age, and compares it to an old pickup truck.

With Mr. Sagely at the controls, the two men reached Malibu, but the fire had already been put out on the ground.

At 6:23 p.m., the order came to divert to Eaton Canyon, where five minutes earlier a 911 caller had alerted the department to the growing fire. Two other helicopters, a Bell 412 and a Firehawk, both equipped with water tanks, took off from the department’s base to join Copter 17 at the fire.

Typically pilots take off, find a reservoir near the fire, drop the aircraft’s giant snorkel into the water and fill their tanks. The pilot then flies close over the flames and presses a button to dump the water.

But as soon as the three helicopters arrived at the fire, they were tossed around by the violent downdrafts — and equally jarring updrafts. During one stomach-churning plunge, Mr. Williams, who was piloting his Bell 412 behind Mr. Sagely’s Copter 17, peered down to his instrument panel and saw that he was falling at a rate of 1,000 feet per minute. He came within 400 feet of the valley floor.

“I knew right away it was going to be potentially catastrophic, pushing the aircraft to the ground,” Mr. Williams said.

The pilots fought the winds with every limb. With their feet they adjusted the tail rotors. With their left hands, they urgently pulled up the collective, a lever used to change altitude, to compensate for the winds shoving them down. With their right hands, they jostled the cyclic stick, the lever that tilts the rotors, to try to keep the aircraft pointed into the wind.

The instruments were telling Mr. Sagely that the air speed hitting the front of his aircraft was 85 knots, around 98 m.p.h. Another indicator told him he was maintaining a ground speed of 11 knots. But when he looked out the window, he realized he was indeed traveling that speed — but backward, pushed by the winds.

At 6:45 p.m., nine minutes after arriving on the scene, Mr. Sagely and Mr. Siok made the difficult decision to cancel water operations. There was nothing they could save.

“Mike! Get the hell out of there! Now!” Mr. Williams radioed to his fellow pilot in front of him.

Mr. Sagely and Mr. Siok stayed another 39 minutes, relaying the path of the firestorm to commanders on the ground. They were the last firefighting helicopter in the air that night. All other aircraft had been grounded.

Touching down in Pacoima, their fuel nearly depleted, they saw the Air Operations Section in battle mode, already gearing up for the winds to calm down and the next stage to begin. Mr. Blumenthal’s mechanics began rushing a mothballed, decades-old helicopter back into service.

The county air teams flew 170 hours in the seven days after the Eaton fire broke out — more hours in a week than they typically fly in the entire month of January.

Still, Mr. Sagely describes the night of Jan. 7 as a failure.

“You are expected to try and save the day — and sometimes you have to let that go,” he said. “There are times when you cannot do anything. You are watching it play out and you are helpless to change it.”

He takes solace in the work he and other pilots did when the winds died down, the homes they saved in the many fires, big and small, that the department was called in to fight.

On Wednesday, more than a week after the Los Angeles infernos erupted, a sergeant for the Los Angeles Police Department, Jeff Rivera, arrived unannounced at the Air Operations office.

The sergeant had been at his home in Arcadia, east of Altadena, a week earlier, when the winds suddenly picked up and a fire raging in the Angeles National Forest began descending down a hillside toward his house. He and other residents were helpless to stop it.

Out of the sky they heard the thumping sound of helicopter rotors and saw a white aircraft with yellow stripes. It was Copter 15, a Firehawk carrying a full load of water. With his phone, Sergeant Rivera shot a video of the aircraft descending onto the edge of the fire, dropping its load of water and extinguishing a wall of flames.

“They literally saved the entire area,” Sergeant Rivera said in the Air Operations office. “I came here to thank them.”

More than two dozen people had been reported dead in the fires raging around in Los Angeles as of Monday.

Most of them lived in the hillside community of Altadena, near the eastern edge of the city, where the Eaton fire destroyed thousands of structures. Several lived within just a few blocks of one another, near the edge of the Angeles National Forest.

Two of the dead, a man and his son, who had cerebral palsy, had called for help evacuating, but none came. One of the victims was found near a garden hose he had been using to spray his house as the fire bore down.

In the Palisades fire, near the coast, the dead included a hang-glider, a surfer and a former child star from Australia.

Evelyn McClendon, 59, lived surrounded by three generations of her family in the Altadena neighborhood: her mother lived in a separate house on the same property; her brother, Zaire Calvin, lived next door. Mr. Calvin recalled racing to help his wife, his 1-year-old daughter, and his 84-year-old mother evacuate, while yelling to his sister to get in her car.

“I’m still trying to understand why she didn’t leave,” he said.

Ms. McClendon held several corporate jobs before withdrawing to lead a quieter life, Mr. Calvin, 47, said. She was a passionate participant in her online church, and worked as a bus driver for the Pasadena public schools, he said. She once told him that in her years of corporate work, striving for advancement, she wished she had “taken the time to enjoy life. And that stuck with me, always,” he said.

Oswald Altmetz, 75, was known as “Ozzie,” and on Pine Street in Altadena, he was a familiar part of the landscape, like the mountains and old oak trees, his niece Bianka Altmetz said. He loved baseball, old cars and jazz music, which he played nonstop. And he loved his dog, Harley, who died with Mr. Altmetz when fire consumed the home he had lived in since he came to Altadena as a young immigrant from Germany.

His neighbor Elizabeth Richey said she had urged him to leave. “He kept saying, ‘I’ve seen this before; nothing is going to happen,’” she said.

In her childhood, Bianka Altmetz said, Mr. Altmetz took his young relatives hiking to waterfalls and swimming in mountain pools. He was “the fun uncle, the one who always had the treats and cookies you weren’t supposed to have,” she said.

Dalyce Curry, 95, died inside her home in Altadena. Ms. Curry had been an actress and an extra in several films, including “The Ten Commandments,” “Lady Sings the Blues,” and “The Blues Brothers.” Into her 90s, she dressed up and kept fit, her granddaughter, Dalyce Kelley, said.

But Ms. Curry had spent the day in the hospital for a cardiac issue, and her granddaughter dropped her off that evening, thinking she was safe. Ms. Kelley said she now felt guilty about leaving her. “No one saw this coming,” Ms. Kelley said. “I’ve never seen this type of devastation in my lifetime living in this city, and she loved Altadena so much.”

“It was her safe place,” Ms. Kelley said, adding “it’s unfortunate that her safe place became a nightmare.”

Anthony Mitchell, 68, died with his son Justin, who had cerebral palsy and was in his 30s. His other children heard from Mr. Mitchell, who used a wheelchair, as the fire was bearing down on Altadena. He said he expected someone to come help the two evacuate. By 8 that night, he and Justin had both been found dead.

“I felt the system let them down,” his son Anthony Mitchell Jr. said.

Justin Mitchell was known for his sunny personality and love of reading. Mr. Mitchell was known for his barbecuing skills and his care for his family and for his neighbors. “My dad was just one of those people,” Anthony Mitchell Jr. said. “You would meet him and he would make friends with you real quick.”

Victor Shaw, 66, died trying to save his tile-roof house on Monterosa Drive, a cul-de-sac near the edge of the forest. “The house had a whole lot of significance for him,” a neighbor, Willie Jackson, 81, said. “His parents had always had it.”

Mr. Shaw drove a bloodmobile and made deliveries. “He was hard-working,” Mr. Jackson said.

After the fire passed, neighbors and family members came to search for him. They found him lying in his front yard clutching a garden hose. “He was out here trying to fight the fire by himself,” Mr. Jackson's son, William, said.

Rodney Nickerson, 82, died in his home just a short walk from Mr. Shaw’s. Mr. Nickerson was a retired aerospace engineer for Lockheed Martin and an active deacon at his church, according to his son Eric Nickerson.

Mr. Nickerson loved to fish, play the horses and watch the San Francisco 49ers, his daughter-in-law, Elsa Nickerson, said in an interview. And he was deeply attached to his house, where he had raised his two children, and the neighborhood, where he had seen the cycle of generations. His family urged him to evacuate, but he told them he believed the fire would not reach him.

Erliene Kelley was a retired Rite Aid pharmacy technician and a longtime resident of the same section of Altadena, according to Rita and Terry Pyburn, a couple who lived on her block.

“She was so, so, so sweet,” Terry Pyburn said.

“It was panic. Everyone took off and no one thought to check on anybody,” Mr. Pyburn said, adding, “I think the notice came too late.”

Kim Winiecki, 77, moved to her house in Altadena about 35 years ago. “Her home was her security, her everything,” Jeannette McMahon, a close friend, said in a phone interview.

Ms. Winiecki was a deeply private person and never let anyone on or near her property. “We respected that,” Ms. McMahon said, “even though I was her closest friend.”

When the Eaton fire broke out near Ms. Winiecki’s house on Tuesday, Ms. McMahon said she offered her a ride out, but Ms. Winiecki said she would stay put and wait out the fire.

Mark Shterenberg, 80, was likely one of the first to die in the Palisades fire, based on Los Angeles County fire dispatch transmissions. His granddaughter, Tatiana Bedi, said he was deeply devoted to his family.

“My heart just feels like he was protecting everything that he worked so hard for his whole life to build for his family,” Ms. Bedi said.

Mr. Shterenberg was born in the Soviet Union and emigrated to the United States in 1980. He earned a master’s degree from Pepperdine University and was the top of his class, his granddaughter said. Ever an inspiration to his grandchildren, Mr. Shterenberg ran three miles every morning, including on the day he died. His motto, Ms. Bedi said, was: “Study math, keep money in the bank, and do three good things, every day.”

Charles Mortimer, 84, a longtime resident of Pacific Palisades, was a Chicago Cubs fan with a quick wit and an infectious smile, his family said in a statement shared by his niece, Meredith Mortimer.

“Charlie Mortimer truly lived life to its fullest,” the statement said. “He was a world traveler, a sun worshiper, and an avid sports fan.”

Mr. Mortimer died in the hospital on Jan. 8, having suffered a heart attack, smoke inhalation and burns, according to the Los Angeles County Medical Examiner.

Arthur Simoneau, a beloved figure in the hang gliding community, died in the Palisades fire while trying to save his home in Topanga, his family said.

Mr. Simoneau was a member of the Sylmar Hang Gliding Association, where he served as a mentor to many, according to Steve Murillo, the association’s president. A GoFundMe page set up by his son, Andre Simoneau, described Mr. Simoneau as a man who showed others how to live with a rare “childlike eagerness.”

“It was always in the back of our heads that he would die in spectacular Arthur fashion,” the post read. He died protecting his home, the post said, “something only he was brave enough (or crazy enough) to do.”

Randall Miod, 55, was a “legend in Malibu” who lived and died in the place he loved most, his mother, Carol A. Smith, wrote in a statement. Surfing had been his passion from youth. Since his 20s, he had lived in the same house on the Pacific Coast Highway, which became a gathering place for friends. Kristin Miod Ennabe, his cousin, likened him to Peter Pan and said he had a “gentle spirit” like his father, Lawrence Miod.

Ms. Smith said the last time she spoke with her son was the day the Palisades fire began. He called her, nearly in tears, and she urged him to take himself and his cat to a shelter. Instead, Mr. Miod stayed. His final words to her were: “Pray for the Palisades and pray for Malibu. I love you,” she wrote.

Rory Sykes, 32, a former child star from Australia who was born with cerebral palsy, died in the Palisades fire, according to his mother, Shelley Sykes. Mr. Sykes appeared in the 1990s British television show “Kiddy Kapers.” On his website, he described himself as a gamer, investor and philanthropist.

“He was just a beautiful soul,” Ms. Sykes said.

The two moved to the United State in 2010 and had lived on a 17-acre estate in the Malibu area for the last decade. Mr. Sykes had his own cottage, which burned after he told Ms. Sykes he wasn’t leaving and locked himself inside, she said.

Troy Closson, Anemona Hartocollis, Shaila Dewan and Nicholas Bogel-Burroughs contributed reporting. Susan C. Beachy, Alain Delaquérière, Sheelagh McNeill and Kitty Bennett contributed research.

After disasters like the Los Angeles wildfires, the Federal Emergency Management Agency offers different types of financial assistance. The fastest is what FEMA calls “serious needs assistance,” which is a one-time payment of $770. That money is meant to be used for immediate needs, such as food or other supplies, for people who had to leave their homes.

You can apply for the $770 payment online, at www.disasterassistance.gov. You can also call FEMA at 1-800-621-FEMA (1-800-621-3362).

That one-time payment for disaster survivors is a relatively new program, introduced by FEMA a year ago. The program is a grant, not a loan: If you get the $770 from FEMA, you do not need to pay it back.

It’s also important to know that the $770 payment is not the only help that FEMA offers. The agency also offers a range of help through its “individual assistance program,” which pays for things like car damage, medical bills or even funeral costs. That money, which is also a grant (which means you don’t need to repay it) can be as much as $43,600. FEMA also offers grants to help repair damage to your home.

However, those additional assistance programs typically take longer.

Many disaster survivors also seek help through crowdfunding sites like GoFundMe. According to FEMA, getting money from GoFundMe can sometimes make people ineligible for money from FEMA for the same expense. FEMA has more information about that on its website.

There are other federal disaster assistance programs, including low-interest loans from the Small Business Administration to repair your house, which go beyond the grants that FEMA offers. But your first step should be applying for help from FEMA.