Watch: View of Baltimore bridge wreckage as massive crane arrives for clean-up

Watch a view of the Francis Scott Key Bridge in Baltimore on Saturday 30 March.

Cranes have started to arrive in the area to help clear the wreckage of the collapsed structure — an essential step before recovery efforts to find the missing construction workers continue, officials say.

One of the cranes, the Chesapeake 1000, is capable of lifting 1,000 tonnes — but the bridge is estimated to weigh around three or four times that, so it will need to be cut into sections, Maryland governor Wes Moore said.

State and federal authorities are focused on clearing the busy port and rebuilding the bridge after the Dali, a massive container ship that had lost power, crashed into a support column early on Tuesday, toppling the structure and leaving six workers presumed dead.

Divers have recovered two bodies of the missing construction workers, who were repairing the bridge at the time of the collision.

The remaining four are believed to be trapped beneath the water. All were immigrants from Mexico and Central America.