Emergency workers have suspended the search for six people missing after a major bridge collapsed in the US city of Baltimore, when a massive cargo ship crashed into the structure.
US Coast Guard and Maryland State Police officials said that based on the frigid temperature of the water and the length of time that had elapsed since the bridge came down, there was little if any chance that the six missing could be found alive.
The Singapore-flagged container vessel named Dali, heading out of the harbour bound for Sri Lanka, crashed into a support pylon of the Francis Scott Key Bridge over the mouth of the Patapsco River at about 1.30am (5.30am Irish time).
A section of the of the 2.57km span almost immediately crumpled into the icy water, sending vehicles and people into the river.
Rescuers pulled two survivors to safety, one of whom was hospitalised. But active search-and-rescue operations were suspended about 18 hours after the tragedy, authorities said.
The eight individuals were part of a work crew filling potholes on the road surface of the bridge when the accident occurred, officials said earlier.
The ship reported a power failure before impact, which enabled officials to stop traffic on the bridge before the collapse.
The incident has forced the closure of one of the busiest ports on the US Eastern Seaboard.
"By being able to stop cars from coming over the bridge, these people are heroes. They saved lives last night," Maryland Governor Wes Moore said at a news briefing hours later.
The bridge was up to code and there were no known structural issues, Mr Moore said.
There was no evidence of foul play, officials said.
US President Joe Biden has called the collapse of the bridge in Baltimore a "terrible accident".
He has pledged to get the major east coast port up and running as soon as possible and said he would send "all the federal resources" needed to handle the incident.
"I'm directing my team to move heaven and earth to reopen the port and rebuild the bridge as soon as humanly possible," Mr Biden said in a brief address from the White House.
However, he acknowledged: "This is going to take some time."
The bridge was up to code and there were no known structural issues, Mr Moore said. He said the vessel's crew members notified authorities of a power issue on board before the crash.
Jayme Krause was in the midst of another night shift at her workplace on shore when the cart of packages in front of her shook violently at around 2am. A co-worker told her the bridge had collapsed and she ran out to look.
"I went over there, and sure as anything, it was gone, the whole bridge was just like, there was nothing there," she told Reuters in an interview. "It was a shocking sight to see."
The ship "lost propulsion" as it was leaving port, and crew on board notified Maryland officials they had lost control of the vessel, ABC News reported, citing an unclassified US intelligence report.
Traffic was suspended at the Port of Baltimore until further notice, Maryland transportation authorities said. It is the busiest US port for car shipments, handling more than 750,000 vehicles in 2022, according to port data.
The closure of one of the US east coast's major ports threatens to disrupt supplies of goods from cars, to coal and other commodities like sugar. It could create bottlenecks and increase delays and costs on the Northeastern seaboard, experts say. The port handles the most car imports and is among the largest for coal exports.
The Francis Scott Key bridge was the main thoroughfare for drivers between New York and Washington who sought to avoid downtown Baltimore. It was one of three ways to cross the Baltimore Harbour, with a traffic volume of 31,000 cars per day or 11.3 million vehicles a year.
The ship was identified as the Dali, owned by Grace Ocean Pte Ltd and managed by Synergy Marine Corp. Synergy said the Dali collided with one of the pillars of the bridge and that all its crew members, including the two pilots, had been accounted for and there were no reports of any injuries.
Baltimore Mayor Brandon Scott described a scene of twisted metal shooting into the sky. "It was something out of an action movie. It was something you never thought you'd see," he said.
Kevin Cartwright, the spokesperson for Baltimore City Fire Department, earlier told Reuters that as many as 20 people could be in the river along with cars and possibly a tractor-trailer.
"This is a mass-casualty, multi-agency event," he said. "This operation is going to extend for many days."
A live video posted on YouTube showed the ship ploughing into the bridge in darkness. The headlights of vehicles could be seen on the bridge as it crashed into the water and the ship caught fire.
The disaster may be the worst US bridge collapse since 2007 when the I-35W bridge in Minneapolis collapsed into the Mississippi River, killing 13.
It was the first major collapse of a bridge from a ship impact in about 40 or 50 years, David Knight, a specialist at the Institution of Civil Engineers, told Reuters.
The National Transportation Safety Board was sending a team to investigate.
Mr Moore declared a state of emergency to quickly deploy federal resources to deal with the emergency. The FBI in Baltimore said on social media its personnel were on the scene.
The Dali was chartered by shipping company Maersk at the time of the incident, the Danish company said in a statement.
"We are horrified by what has happened in Baltimore, and our thoughts are with all of those affected," Maersk said.
Baltimore port's private and public terminals handled 847,158 autos and light trucks in 2023, the most of any US port. The port also handles farm and construction machinery, sugar, gypsum and coal, according to a Maryland government website.
The port handles imports and exports for major manufacturers including Nissan, Toyota, General Motors, Volvo, Jaguar Land Rover and the Volkswagen group - including luxury models for Audi, Lamborghini and Bentley.
More than 40 ships remained inside Baltimore port including small cargo ships, tug boats and pleasure craft, data from ship tracking and maritime analytics provider Marine Traffic showed.
At least 30 other ships had signalled their destination was Baltimore, the data showed.
The bridge, named after Francis Scott Key, author of the Star Spangled Banner, opened in 1977.
