An Interstate 5 highway bridge collapsed in Mount Vernon, Washington Thursday night, leaving three people injured after their cars plummeted into the Skagit River, reports ABC News.
The collapse, which happened around 7 p.m., sent three people to the hospital. People were sitting on top of their vehicles in the water as rescue boats arrived at the scene.
Investigators believe the cause of the collapse was a semi-truck that hit the bridge, snapping a steel truss.
"An 18-wheeler commercial motor vehicle with a very large container appears to have struck part of the bridge at some point," Washington State Trooper Mark Francis said.
Dan Sligh was on his way to a Memorial Day camping trip with his wife when the bridge went down with him on it. The impact dislocated his shoulder.
"Rough day," Sligh said. "Glad to be here breathing."
The bridge was built in 1955 and although it was not considered structurally deficient, its design was outdated.