Crews in the US are scheduled to conduct a controlled demolition to break down the largest remaining span of the Francis Scott Key Bridge, which collapsed when it was hit by a massive container ship.

The steel span landed on the ship’s bow after the Dali lost power and crashed into one of the bridge’s support columns shortly after leaving Baltimore, in the US state of Maryland, on March 26.

Since then, the ship has been stuck among the wreckage and Baltimore’s busy port has been closed to most maritime traffic.

Six members of a road work crew filling potholes on an overnight shift plunged to their deaths when the bridge was destroyed.

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The last of their bodies was recovered from the underwater wreckage during the week.

All the victims were Latino immigrants who came to the US for job opportunities.

The controlled demolition will allow the Dali to be refloated and guided back into the Port of Baltimore.

Once the ship is removed, maritime traffic can begin returning to normal, which will provide relief for thousands of longshoremen, truckers and small business owners whose jobs have been impacted by the closure.

The Dali’s 21-member crew will shelter in place aboard the ship while the explosives are detonated.

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Crew spokesman William Marks said they would shelter “in a designated safe place” during the demolition.

“All precautions are being taken to ensure everyone’s safety,” he said in an email.

In a video released during the week, authorities said engineers were using precision cuts to control how the trusses broke down.

They said the method allowed for “surgical precision” and was one of the safest and most efficient ways to remove steel under a high level of tension.

The steel structure will be “thrust away from the Dali” when the explosives send it tumbling into the water, according to the video.

Once it’s demolished, hydraulic grabbers will lift the resulting sections of steel onto barges.

“It’s important to note that this controlled demolition is not like what you would see in a movie,” the video said, noting that from a distance it will sound like fireworks or thunder and give off puffs of smoke.

Officials previously said they hoped to have removed the Dali by Friday and reopen the port’s main channel by the end of May.

The Dali crew members – 20 from India and one Sri Lankan – have not been allowed to leave the grounded vessel since the disaster.

Officials said they have been busy maintaining the ship and assisting investigators.

The National Transportation Safety Board and the FBI are conducting investigations into the bridge collapse.

Danish shipping giant Maersk chartered the Dali for a planned trip from Baltimore to Sri Lanka, but the ship did not get far.

Its crew sent a mayday call saying they had lost power and had no control of the steering system.

Minutes later, the ship rammed into the bridge.

Officials have said the safety board investigation will focus on the ship’s electrical system.

-AP