What led to Francis Scott Key Bridge collapse in Baltimore?

Mass casualties are feared after a ship collided with a pillar of the Francis Scott Key Bridge in Baltimore, Maryland.

US media reports suggest that at least seven people dropped into the Patapsco River, on which the bridge is built.

Moments after the incident, Synergy Marine Group confirmed that its Singapore-flagged container ship 'Dali' collided with the bridge’s pillar, Reuters reported.

"Whilst the exact cause of the incident is yet to be determined, the 'Dali' has now mobilised its Qualified Individual Incident response service," the company said.

It added that no crew member was injured and all of them were accounted for.

Footage circulating on social media showed that the bridge collapsed when the vessel, heading to Sri Lanaka’s Colombo, crashed into it. The ship caught fire and smoke billowed from the vessel after it crashed.

It is still unclear how many cars fell into the water; however, CBS News reported that a tractor-trailer was on the bridge when it came down.

Transport chiefs, in a statement, said that the bridge has been closed to traffic. "I can confirm at 1:35am, Baltimore City police were notified of a partial bridge collapse, with workers possibly in the water, at the Francis Scott Key Bridge," a cop said.

"Emergency personnel are on scene, and efforts are underway," Brendon Scott, the city's mayor, said on X, formerly known as Twitter.