BALTIMORE, United States (AFP) — Workers have lifted out the first, 200-tonne chunk of Baltimore’s collapsed bridge, officials said Sunday, as efforts get underway to clear the harbor of the steel structure destroyed by an out-of-control ship.

Demolition crews using blow torches sliced through the upper part of the Francis Scott Key Bridge, which crumbled when the Dali cargo vessel lost power and struck it on Tuesday, killing six people.

Authorities hope that removing the bridge — by cutting it into smaller sections and lifting them out — will help rescuers recover all the victims’ bodies as well as reopen the crucial shipping lane.

“The first lift was made last night after the cutting of the top portion of one of the northern sections of the Key Bridge was completed,” said US Coast Guard spokeswoman Kimberly Reaves in a statement.

“The piece removed last night was approximately 200 tonnes,” she said, adding it would be moved to a barge that, once filled with additional pieces, would be taken to a debris-holding site on land.

As salvage operations continued Sunday, Maryland Governor Wes Moore said that “progress is beginning to happen despite the fact that it’s an incredibly complicated situation.”

He said adverse weather conditions and underwater debris meant divers were unable to assist.

Moore told CNN that a huge crane — the Chesapeake 1,000 that can lift 1,000 tons — was being used in the salvage operation.

However, the multi-agency task force overseeing the operation said two smaller cranes — one weighing 650 tonnes and another at 330 tonnes — were actually being used in this work.

Video footage shared Saturday by the Unified Command — the overall response team that includes the US Coast Guard — showed sparks flying as crews suspended in cages cut through an upper section of bridge.

Moore said the recovery would be a “long road,” adding “but movement is happening.”

The difficult conditions have hampered efforts to recover the bodies of the road workers — all Latino immigrants — who died when the bridge collapsed, with just two of six bodies recovered so far.

Shipping in and out of Baltimore — one of the United States’ busiest ports — has been halted, with the waterway impassable due to the sprawling wreckage.

Moore told MSNBC on Sunday that his priorities were recovering the victims’ bodies before reopening the channel.

“It’s impacting the nation’s economy. It’s the largest port for new cars, heavy trucks, and agricultural equipment. It’s impacting people all over the country,” he said.

The ship veered towards the bridge due to power trouble, with the pilot issuing a Mayday call that allowed some road traffic to be stopped just before the collision at 1:30 am after which the structure collapsed in seconds.

Transportation Secretary Pete Buttigieg told “Face the Nation” on CBS that there was no timeline to clear the harbour and reopen the port.