The cargo ship Dali is stuck under part of the structure of the Francis Scott Key Bridge after the ship hit the bridge. Image Credit: AP

A salvage firm that helped contain the Deepwater Horizon oil spill and safely blow up part of New York's Tappan Zee Bridge is heading to Baltimore as a first step to what will likely become a more than $2 billion rebuilding project.

Resolve Marine has started mobilizing resources to re-float and remove the ship that smashed into the Francis Scott Key Bridge, said US Coast Guard Vice Admiral Peter Gautier. The accident this week destroyed the span, killed six people and shut down Baltimore's port, threatening to disrupt global supply chains and the livelihoods of thousands of workers.

Federal officials told Maryland lawmakers that replacing the 1.6-mile (2.6-kilometer) bridge would cost at least $2 billion including cleanup, said a person familiar with the matter.

"Consistent with the president's direction to get the port up and running as soon as possible, the Coast Guard's highest priority now is restoring the waterway for shipping, stabilizing the motor vessel Dali and removing it," Gautier said Wednesday at a White House press conference.

The Singapore-flagged Dali, a 984-foot (300-meter) container ship, slammed into the bridge and brought down the entire structure within seconds on March 26. The vessel couldn't maintain its desired heading after experiencing a loss of propulsion, but the reason for the failure remains under investigation by the National Transportation Safety Board.

Six construction workers who were on the bridge at the time of the collision are presumed dead after a search-and-rescue effort. The Washington Post described them as fathers and husbands from Mexico, Guatemala, Honduras and El Salvador. The Baltimore Banner reported that the bodies of two men had been recovered, citing people with knowledge of the operation. The bodies were found inside a vehicle and brought to shore, the news website said.

The Dali is carrying about 4,700 cargo containers, including 56 that contain hazardous materials, Gautier said.

The Coast Guard is working with the Army Corps of Engineers, which is leading the salvage effort, and both have moved "aggressively" to board the vessel and ensure it remains stable since it holds more than 1.5 million gallons of fuel and lube oil on board, Gautier said. A portion of the bridge remains on the bow of the ship, which is sitting at the bottom of the channel but doesn't appear to have any flooding, he said. That debris needs to be removed first before the ship can be re-floated.

Resolve Marine, based in Fort Lauderdale, Florida, has experience with bulk: In addition to its demolition work on the Tappan Zee, it also served as a contractor in removing the New York bridge's span structure.

It's too soon to set a timeline for the port's reopening, according to US Transportation Secretary Pete Buttigieg, but outside estimates range from a couple weeks to more than a month. The closure is threatening the livelihoods of thousands of workers, while a dozen large ships are stuck inside Baltimore's harbor and trade is being rerouted to other ports.

"This isn't going to happen overnight," Buttigieg said in an interview with Bloomberg Television. "This isn't going to be cheap either."

Buttigieg said that rebuilding a smaller Minnesota bridge that collapsed in 2007 cost around $260 million, but warned the Key Bridge reconstruction would be pricier.

"This is a larger span of a bridge, likely in many ways a more complex project," he told Bloomberg TV. "We just don't know the full scope yet."