BALTIMORE, United States (AFP)— Emergency services combed the cold waters of Baltimore harbour Wednesday in search of the bodies of six men — all reported to be Latin American immigrants — presumed killed when a giant cargo ship slammed into the bridge where they working the night shift fixing potholes.

Police and Coast Guard crews swarmed the disaster site, with specialised divers scouring the river under the destroyed Francis Scott Key Bridge. Their task, however, was limited to recovering bodies.

“We do not believe any of these individuals are still alive,” the regional Coast Guard chief, Rear Admiral Shannon Gilreath, said.

The container ship Dali, almost a kilometre (0.6 mile) long and piled high with cargo, was leaving the busy port at 1:30 am Tuesday en route to Asia when power failed and the vessel crashed straight into one of the columns supporting the steel bridge — a major crossing point used by tens of thousands of motorists a day.

Nearly the entire structure collapsed instantly, cascading over the bow of the ship, which remained entangled in the debris Wednesday, blocking one of the busiest US trading ports.

In dramatic scenes, police managed to stop vehicles from driving onto the bridge as soon as they received a Mayday call from the ship to warn of the impending collision.

But there was no chance to evacuate the eight men filling potholes on the road directly above the massive ship.

Officials said that two of them were pulled from the water, one of them seriously injured and the second unharmed. The other six vanished into the swirling currents and crumpled tangle of wrecked girders and pylons.

“We do not know where they are,” Maryland state police officer Roland Butler told US media. “We intend to give it our best effort to help these families find closure.”

Details emerged in US media about the identities of the men labouring on the bridge at night, ahead of the next day’s heavy rush hour traffic.

The Baltimore Banner reported that they were from El Salvador, Guatemala, Honduras and Mexico.

“They are all hard-working, humble men,” Jesus Campos, a colleague of the eight workers all employed by contractor Brawner Builders, said.

One of those now presumed dead was father-of-three Miguel Luna, according to Casa, a nonprofit that serves immigrant communities.

Luna, from El Salvador, had left for work at 6:30 pm on Monday and never returned, Casa said.

His wife, Maria del Carmen Castellon, told Telemundo 44 that she was “devastated” by the wait for any information.

“My heart hurts with this situation,” said Campos.

“They’re human beings and they are my colleagues.”

Footage of the collision showed the vessel slamming into one of the 47-year-old bridge’s supports.

“Just prior to the incident, the vessel, Dali, had experienced momentary loss of propulsion. As a result, it was unable to maintain the desired heading,” said the maritime authority for Singapore, where the ship is flagged.

The authority said the ship’s management company, Synergy Marine Pte Ltd, reported the crew “dropped anchors” in a last-ditch, failed attempt to hold it back.

The ship had passed two overseas inspections in 2023, the authority said Wednesday, adding that a fault monitor gauge was fixed in June.

Investigators from the authority and Singapore’s Transport Safety Investigation Bureau headed to Baltimore to assist the US Coast Guard.

The Port of Baltimore is the ninth-busiest major US port in terms of both foreign cargo handled and foreign cargo value, and is directly responsible for more than 15,000 jobs, supporting almost 140,000 more.

US President Joe Biden called the collapse a “terrible accident,” and pledged to get the port reopened and the bridge rebuilt.