The Maryland Transportation Authority took the first step Thursday toward building a replacement for the toppled Francis Scott Key Bridge when it awarded a contract to construction giant Kiewit for the project’s first phase.

The selection marks a notable chapter in the five-months-long saga of the Key Bridge collapse and aftermath.

In the early hours of March 26, an adrift , massive container ship named the Dali crashed into the bridge, sending 50,000 tons of steel and roadway into the river below and killing six construction workers filling potholes on the span. That blocked the shipping channel underneath — the Port of Baltimore’s principal commercial artery — for a little more than two months.

The port continues to recover economically from the shipping shutdown and the bridge’s absence can be felt by any commuter or shipper seeking to cross the harbor.

The $73 million contract awarded to Omaha, Nebraska-based Kiewit Corp. is a down payment on what is expected to be at least a $1.7 billion project to replace the Key Bridge over the Patapsco River.

Although a contractor has been identified, the specifics of the new bridge have not been decided. The new span is expected to open, though, by October 2028 and likely to be cable-stayed — meaning it would have tall towers, similar to a suspension bridge, with a web of cables connected to the bridge’s deck, or roadway — and will be taller, longer and slightly wider than the old truss bridge.

The new span’s vertical clearance will be at least 230 feet , substantially higher than the old height of 185 feet, and it will be longer to allow the roadway to reach the increased height without requiring drivers to climb a steep incline. The span will be built on the same center line as the old bridge and, like the felled structure, will have four lanes , although the shoulders will be substantially wider in accordance with updated federal bridge code.

The new bridge will be constructed using a design-build method, allowing construction to begin even as the planning process is ongoing, in an effort to expedite the structure’s opening.

Kiewit has experience with design-builds and with using that method to construct a cable-stayed span; it was among the builders of the cable-stayed Port Mann Bridge in British Columbia, Canada, which opened in 2012.

Kiewit is involved in another large transportation project in Maryland: the Frederick Douglas Tunnel , which will accommodate rail traffic and replace Amtrak’s Baltimore and Potomac Tunnel under West Baltimore. Kiewit is taking on that project, estimated to cost roughly $6 billion in total, with California-based J.F. Shea Construction Inc.

Kiewit shared on social media in June that it was “assembling a team to respond to the anticipated request for proposals” for the Key Bridge rebuild, but a spokesperson declined to comment at the time, telling The Baltimore Sun in an email: “Kiewit does not publicly discuss the work we potentially pursue.”

One of Kiewit’s first tasks — in addition to designing the new bridge alongside the transportation authority — will be ridding the Patapsco River of the old bridge’s vestiges. The ramps-to-nowhere that remain, as well as the artificial, concrete islands (called “dolphins”) designed to protect the piers will be blasted and demolished either this fall or in the spring.

Then, the construction can begin. The federal government is expected to foot the bulk of the $1.7 billion bill. Democratic President Joe Biden promised immediately after the collapse that the federal government would pay for 100% of the rebuild, but that has yet to be coded into law. The default for any interstate project is for the federal government to pay 90% of the cost; in that situation, Maryland would be on the hook for roughly $170 million.

Maryland Sen. Ben Cardin, a Democrat, said this month of the federal government covering the entire cost: “We’re on our way to get that legislation passed.”

Federal authorities also have said they’ll seek to reimburse themselves with funds from culpable parties — such as the container ship’s owner and manager.

Small businesses and the City of Baltimore have already filed suit against the Singaporean owner and manager Grace Ocean Private Ltd. and Synergy Marine Group, respectively. A local propane transportation company this week stated in a federal filing that it has “lost profits and lost business” as a result of the collapse and that “an example should be made of” the ship’s owners.