Six repairmen, who were working on a bridge that collapsed in the United States’ Baltimore on Tuesday after a cargo ship collided with it, were missing and presumed dead, reported Reuters.

The cargo ship Dali collided with a pillar of the Francis Scott Key Bridge around 1.30 am, causing the structure to collapse into the Patapsco River. Several persons and cars on the bridge fell into the river.

The Singapore-flagged vessel was on its way from Baltimore to Colombo. The entire 22-member crew of the ship were Indians.

All crew members, including the two pilots, were accounted for and there were no reports of any injuries among them, said Synergy Marine, the company that manages the ship.

However, the six repairmen were not found even 18 hours after the accident. Coast Guard Rear Admiral Shannon Gilreath said there was no hope of finding the missing workers alive due to the frigid water and the length of time elapsed since the accident.

The rescue operation, officials hope, would resume on Wednesday morning.

Rescuers had earlier pulled out two people to safety, one of whom was hospitalised.

Wes Moore, the governor of Maryland, where Baltimore is located, has declared a state of emergency. “We are working with an interagency team to quickly deploy federal resources from the Biden Administration,” Moore said in a social media post.

He added: “We are thankful for the brave men and women who are carrying out efforts to rescue those involved and pray for everyone’s safety.”

United States President Joe Biden commended the crew members onboard the vessel for their prompt mayday call.

“Personnel on board the ship were able to alert the Maryland Department of Transportation that they had lost control of their vessel, as you all know and have reported,” Biden said in his address on Tuesday. “As a result, local authorities were able to close the bridge to traffic before the bridge was struck, which undoubtedly saved lives.”

The US president also said the US Coast Guard responded quickly to the mayday call. He promised to visit Baltimore as soon as possible and said he wanted the federal government to pay to rebuild the bridge.

"I am directing my team to move heaven and Earth to reopen the port and rebuild the bridge as soon as humanly possible," said Biden.