Baltimore's biggest bridge collapses after being hit by a cargo ship, videos show. Mass casualty event declared.

• Baltimore's Francis Scott Key Bridge collapsed early on Tuesday morning.
• A livestream captured the moment a ship collided with one of the bridge's support beams.
• Authorities are calling it a "mass casualty event" and say 20 people went into the water.

Baltimore's Francis Scott Key Bridge collapsed on Tuesday morning after it was struck by a large container ship.

A video of the incident was posted early on Tuesday morning to X, formerly Twitter. In the video, the container ship the Dali is seen colliding with one of the bridge's support beams. Smoke is seen billowing from the ship before the bridge began crumbling.