The Francis Scott Key Bridge along I-695 in Maryland collapsed into the Baltimore harbor early Tuesday morning following a “ship strike,” Maryland transportation officials said.

A livestream of the bridge appeared to show a cargo ship colliding with a support beam, causing the bridge to break and fall into the Patapsco River. Multiple vehicles were on the bridge at the time.

Emergency crews were searching for at least seven people believed to be in the water, Kevin Cartwright, director of communications for the Baltimore Fire Department, told The Associated Press around 3 a.m. Officials have described this as a mass casualty event. There were no specific number of deceased.