Lessons from Skyway disaster failed to help protect Baltimore bridge

After the Sunshine Skyway bridge was hit by a freighter and collapsed in 1980, new protection measures were installed around the supports that hold the bridge up.

Engineers put in place island-like mounds of rocks that shore up the tallest support columns and huge, disc-like structures called dolphins that act as bumpers blocking wayward ships. Engineers around the country followed suit to help strengthen bridge protections.

But when a ship struck the Francis Scott Key Bridge in Baltimore on Tuesday...