An interstate highway bridge over the Skagit River in Washington State collapsed Thursday evening (May 23), injuring three.
The bridge, located about 60 miles (nearly 100 kilometers) north of Seattle on I-5, collapsed after being struck by an 18-wheel truck carrying a drill rig, various news sources reported.
The bridge, which was built in 1955, was rated as functionally obsolete — basically old — and fracture critical, MyNorthwest.com reported. That designation means there was no redundancy built into the structure of the bridge, so that if any structural component was damaged, the bridge could not support itself. About 18,000 bridges in the United States are designated as functionally obsolete.