Smoke was seen rising from the cargo vessel that crashed into the Francis Scott Key Bridge bridge.
It appeared that there was an explosion on the ship.
The vessel was a Singapore-flagged cargo ship heading to Colombo, Sri Lanka, per the New York Times.
At least seven people are in the water and a rescue operation has been launched, per WBAL.
First responders are preparing for a mass casualty incident, according to reports.
The number of cars in the water remains unknown at this time.
At around 1:30am ET, a "large vessel" hit the Scott Key Bridge bridge, Chief Kevin Cartwright, director of communications for the Baltimore City Fire Department told the BBC.
It is currently unknown how many people, if any, were on the bridge at the time.
But a rescue operation is now reportedly underway, led by the fire department and US coastguard.
The Maryland Transport Authority has confirmed all lanes are closed leading to the Francis Scott Key Bridge bridge.
Traffic is being diverted along the I-95, the authority confirmed on X.
At around 1:30am on Tuesday, a cargo ship was seen hitting the Francis Scott Key Bridge bridge, destroying large sections of it.
Chief Kevin Cartwright, director of communications for the Baltimore City Fire Department confirmed to the BBC that a "large vessel" hit the bridge.
A rescue operation is now underway.