PHOTOS: Baltimore bridge collapse

Baltimore (WBEN/AP) - A container ship has rammed into a major bridge in Baltimore, causing it to snap and plunge into the river below.

Several vehicles fell into the chilly waters early Tuesday, and rescuers searched for survivors. It was also not clear what caused the cargo ship to crash into the Francis Scott Key Bridge long before the busy morning commute in what one official called a “developing mass casualty event” in a major American city just outside of Washington.

Two people were rescued, and it was not clear how many more might be in the water. The ship crashed into one of the bridge’s supports, causing the structure to snap and buckle at several points and tumble into the water in a matter of seconds.