On August 25, 1974, the 600-foot (180 m) ore carrier Steelton, travelling northbound on the canal, struck and destroyed the bridge.

The removal of the towers from the canal, especially the counterweights (some 300 tons each), necessitated the use of a special heavy-duty floating crane.

The ensuing investigation concluded that the ship failed to blow the whistle to signal its approach and the bridge could not be raised in time.

The ship was a total loss, but no injuries were reported, and Bridge 11 suffered minor damage and was repaired.

[3] While repairs were underway, Port Robinson residents wishing to travel by car to other side of the community had to drive even farther than usual to use the Main Street Tunnel in Welland.