The ship's crew issued a mayday call moments before the crash took down the Francis Scott Key Bridge, enabling authorities to limit vehicle traffic on the span, Maryland's governor said

The ship struck one of the bridge's supports, causing the structure to collapse like a toy. A section of the span came to rest on the bow of the vessel, which caught fire

In the evening, Col Roland L Butler Jr, superintendent for Maryland State Police, announced that the search and rescue mission was transitioning to one of search and recovery. He also said the search was being put on pause and divers would return to the site at 6 am Wednesday, when challenging overnight conditions are expected to improve

The crash happened in the middle of the night, long before the busy morning commute on the bridge that stretches 2.6 kilometres and was used by 12 million vehicles last year

The six people still unaccounted for were part of a construction crew filling potholes on the bridge, said Paul Wiedefeld, the state's transportation secretary

A senior executive at the company that employed the workers said Tuesday afternoon that they were presumed dead, given the water's depth and the length of time since the crash

Jeffrey Pritzker, executive vice president of Brawner Builders, said the crew was working in the middle of the bridge when it came down. No bodies have been recovered, and rescuers continued the search into the late afternoon

Jesus Campos, who has worked on the bridge for Brawner Builders and knows members of the crew, said he was told they were on a break and some were sitting in their trucks when the bridge went down

Rescuers pulled two people out of the water. One person was treated at a hospital and discharged hours later. Multiple vehicles also went into the river, although authorities did not believe anyone was inside