Decades later, answers from two scientists who just couldn't "let it go."

What do you know about the Dyatlov Pass Incident? If you don't watch too much X-Files like, er, some of us, here's a refresher: In 1959, nine students and one instructor from the Urals Polytechnic Institute in Yekaterinburg, Russia, headed out into the January cold on a skiing and mountaineering expedition. While one turned back, on February 1, the rest made camp on Kholat Saykhl, translated as "Dead Mountain"—and "were never heard from again." A few weeks later, a search team found their tent almost entirely covered in snow, cut open from the inside. The nine were found dead, their bodies strangely far away from each other, some in a state of undress, some with smashed skulls and chests, some with missing eyes, and one with a missing tongue. 

For decades, the Dyatlov Pass Incident has fueled conspiracy theories. Was it secretive military testing? Yeti? Aliens? In 2019, Russian authorities reopened the cold case and determined it was an avalanche. However, as Robin George Andrews reported for National Geographic this weekend, "Key scientific details were absent from the report ... including a clear explanation as to how an avalanche could have taken place with no documented evidence of its occurrence left behind. This led to continued doubts around the seemingly pat explanation from a government long infamous for its lack of transparency."

An avalanche? How? There was too much time between encampment and time of death, the slope seemed too slight, and the manner of death seemed inconsistent with other avalanche deaths. 

Enter Alexander Puzrin and Johan Gaume, and ... Frozen.

Puzrin, a geotechnical engineer at ETH Zürich, had the answer to the argument that there was "too much time" between the disturbance to the snow (encampment) and the avalanche.

A 2019 paper he co-authored explained, "Most existing models assume that snow slab avalanches happen simultaneously during or immediately after their triggering ... Our model demonstrates that earthquake-triggered delayed avalanches are rare, yet possible, and could lead to significant damage, especially in long milder slopes."

Next, what about that mild slope? Andrews explained, "It turned out not to be all that shallow after all. The undulating topography on Kholat Saykhl, covered by snowfall, made the slope appear mild, but it was actually closer to 30 degrees, the rule-of-thumb minimum requirement for many avalanches. The local topography played a trick on them,” says Puzrin.

Last, the manner of death. Gaume, head of the Snow Avalanche Simulation Laboratory at EPFL, had seen the movie Frozen and was so astonished by how realistic the snow movement was that he traveled to Hollywood to meet with the specialist who created the effect. National Geographic reports that afterward, "Gaume modified the film’s snow animation code for his avalanche simulation models ... to simulate the impacts that avalanches would have on the human body."


Courtesy of Disney (via IMDb)

Using that code, and data from tests General Motors (GM) performed on cadavers in the '70s (to determine seat belt safety), Puzrin and Gaume were able to answer that last question: why, when so many avalanche victims die of asphyxiation, did the eight students and instructor die from blunt force?

Andrews clarified, "Some of the cadavers used in the GM tests were braced with rigid supports while others weren’t, a variable which ended up being serendipitous for Puzrin and Gaume. Back on the slopes of Kholat Saykhl, the team members had placed their bedding atop their skis. This meant that the avalanche, which hit them as they slept, struck an unusually rigid target—and that the GM cadaver experiments from the 1970s could be used to calibrate their impact models with remarkable precision."

"The researchers’ computer models demonstrated that a 16-foot-long block of hefty snow could, in this unique situation, handily break the ribs and skulls of people sleeping on a rigid bed. These injuries would have been severe, but not fatal—at least not immediately," says Puzrin.

This explains, according to Puzrin and Gaume, so many of the strange details that have plagued curious minds for decades. The tent was likely cut open from the inside by those who did not sustain blunt force trauma from the original impact. Since nobody was found inside the tent, "it's likely the more able-bodied survivors dragged the injured out of their smothered shelter in an attempt to rescue them."

Far from being a tale of supernatural phenomena, as Puzrin told National Geographic, "This is a story of courage and friendship." 

Andrews goes on to write, "Most of the nine who perished on Kholat Saykhl died of hypothermia, while others may have succumbed to their injuries. The state of undress some were found in remains puzzling (paradoxical undressing may be an explanation), as do reports that note some of the bodies had traces of radioactivity (which may be a result of thorium present in camping lanterns). The missing eyes and tongue of some victims may have simply been a result of scavenging animals pecking at the dead, but that too remains an open question."

These answers may not be as thrilling as Yeti or alien abduction, but they may, perhaps, serve as a warning. As Andrews puts it, "this freak avalanche would have surprised mountaineering experts with a lifetime of experience." Beyond that, Puzrin and Gaume have done something as impressive as any scientific discovery: they restored an element of care and humanity to the tragic tale of the Dyatlov Pass Incident. 

You can read more of the details of this fascinating story here.

What do you think? Are you as intrigued by stories like this as we are? Tell us in the comments.