• A shipping expert told the BBC that the crash could have been caused by engine failure, steering failure or generator blackout
• Between seven and 20 people are believed to be in the river 

Early on Tuesday morning a container ship crashed into the landmark Francis Scott Key Bridge near the US city of Baltimore, causing most of it to collapse.  
 Several vehicles on the bridge at the time plunged into the waters of the Patapsco River, and rescuers are searching for between seven and 20 people believed to be in the river.  
Maryland Governor Wes Moore has declared a state of emergency.  
Several people were seen to be on the bridge at the time, a fact that was later confirmed by Baltimore Fire Chief James Wallace. Officials later said these included contractors doing repairs to the bridge.  

At 01:50 the first fire department unit arrived on the scene and reported the complete collapse of the bridge.  
A major search and rescue operation is underway, with divers looking for victims in the icy waters of the harbour and the river.  
Officials said there were “some cargo or retainers hanging from the bridge”, creating unsafe and unstable conditions, and that emergency rescue teams were operating cautiously as a result.  
So far two people have been pulled from the water, one in a serious condition and one apparently uninjured, Mr Wallace said.  
The water temperature in the harbour is currently said to be about 9C (48F). Hypothermia can occur when a person’s body temperature drops below 35C.  
The ship set off from Baltimore’s Seagirt Marine Terminal at around 00:24 local time on Tuesday, en route to Colombo, Sri Lanka.  
Video shows that all lights on the exterior of the ship suddenly turned off and smoke began emanating from the ship’s funnel.  
Shortly afterwards it hit the bridge. (BBC)