It's been three weeks since Baltimore's Francis Scott Key Bridge collapsed under the impact of a wayward cargo ship.
The bridge plunged into the Patapsco River in the early morning of March 26 after the massive container ship, Dali, lost power and crashed into a support pylon.
Now, the FBI has launched an investigation and salvage crews are racing against the clock to complete the mammoth clean-up task so the port can be restored to full capacity.
And weeks after the incident, incredible stories of survival are still emerging.
Survivor 'fought for his life'
Julio Cervantes was one of several construction workers whose car plunged into the freezing water when the Dali struck Baltimore's Key Bridge.
"They absolutely got zero warning," one of Mr Cervantes's lawyers, L Chris Stewart, said of the workers during a press conference this week.
"He had no idea. He watched everybody go into the water. They were actually sitting in their cars on break."
Mr Stewart revealed how Mr Cervantes managed to escape his car at the time of the collision.
"He survived because his window was manual. He was able to roll down the window and escape.
"You can imagine how frightening that is."
"He fought for his life and he survived," added Mr Cervantes's other lawyer, Justin Miller.
Fourth body recovered
Six construction workers were killed when the Dali struck one of Baltimore's most essential pieces of infrastructure.
At the time, three bodies were recovered.
This week the body of a fourth victim was recovered after divers spotted what they believed to be a missing construction vehicle, inside which they found the human remains, Key Bridge Unified Command said in a statement.
The victim's identity has not been made public at the request of the family.
The bodies of two workers are still missing.
FBI launches investigation
Meanwhile, the FBI has opened a criminal probe into the collapse of a bridge.
Earlier this week, FBI agents boarded the Dali to conduct court-authorised law-enforcement activity regarding the crash, an FBI spokesperson said, adding the bureau would have no further comment.
The investigation into the collapse will focus in part on whether the crew of the Dali left the port knowing the freighter had serious problems with its systems, the Washington Post reported earlier.
Safety investigators have recovered the ship's black box recorder, which will provide data on its position, speed, heading, radar, and bridge audio and radio communications, as well as its alarms.
The city of Baltimore has hired two law firms — DiCello Levitt and Saltz Mongeluzzi Bendesky Trial Lawyers — as it considers any litigation against the owner, charterer and operator of the ship.
Salvage crews race against clock
Since the collision, crews have been using the largest crane on the United States' eastern seaboard to haul the wreckage to a nearby salvage yard.
The heaviest section so far weighed about 450 tonnes.
In the salvage yard, workers disassemble the metal trusses by attacking them with propane torches and a pair of giant shears that slice them into more manageable pieces.
A Chesapeake 1000 is also being used in the clean-up operation. The floating crane has a storied history that includes helping the CIA retrieve part of a sunken Soviet submarine.
Salvage crews are hoping to recover the two remaining bodies once more of the debris has been removed.
The goal is to open a temporary channel later this month that will allow more commercial traffic to resume passing through the Port of Baltimore, which has remained largely closed since the March 26 collapse.
Officials plan to reopen the port's main channel by the end of May.
So far, more than 1,000 tonnes of steel have been removed from the waterway. But the work is tedious, dangerous and incredibly complex, leaders of the operation have said.
Before removing any pieces of the bridge, divers are tasked with surveying the murky underwater wreckage and assessing how to safely extract the various parts.
Coming up with a road map is among the biggest challenges, according to Robyn Bianchi, an assistant salvage master on the project.
"There's a lot of debris, there's rebar, there's concrete," she said.
"We don't know what dangers are down there, so we have to be very methodical and slow with that."
At the same time, crews are working to remove some containers from the cargo ship Dali before lifting steel spans off its bow and refloating the vessel.
"It presents a dynamic hazard," said Joseph Farrell, CEO of Resolve Marine, which is working on refloating the ship.
He said once that happened, the Dali would return to the Port of Baltimore.
"Getting it out of there is a priority."
How long will it take to rebuild the Baltimore bridge? And who is paying for it?
Rebuilding could be a lengthy process and the size of the task will depend on whether any of the remaining structures can be salvaged.
It took five years to build the original bridge, from 1972 to 1977.
US President Joe Biden has visited Baltimore and pledged federal help to rebuild the span, an idea some Republican politicians have resisted.
In the days after the disaster, the Transportation Department awarded $US60 million ($93.4 million) in "quick release" emergency funds to aid in clearing debris and begin rebuilding.
Federal officials say the final cost of rebuilding the bridge could soar to at least $US2 billion.
To fully replace the bridge, Congress will need to approve funding, and there are growing signs of friction about using federal dollars to fund the bridge's reconstruction.
After the 2007 bridge collapse in Minnesota, Congress allocated $US250 million.
Insurers could face billions of dollars in claims, analysts say, with one putting the cost as high as $US4 billion, which would make the tragedy a record shipping insurance loss.
ABC with wires
