Bridge Collapse Not An Isolated Incident

Today the National Transportation Safety Board begins its investigation of the fatal Minneapolis bridge collapse.

CBS News transportation correspondent Nancy Cordes reported on the previous instances that the NTSB has to draw upon as they conduct their analysis of why the bridge came apart.

Bridge collapses often take place while they are still under the construction process. One bridge in East Chicago killed 12 construction worked in 1982.

But there have been major collapses, like Minneapolis, that had dozens, and sometimes hundreds, of cars crossing when the bridge went down.

One example is the Sunshine Skyway. In 1980, a freighter rammed into this Tampa, Fla. steel cantilever bridge. A large segment of the bridge, along with a Greyhound bus and six cars, plummeted into Tampa Bay, killing 35 people.

In 1983, a 100-foot section of the Mianis River Bridge in Connecticut, a part of I-95, plunged 70 feet into the water. The failure of crucial holding pins was blamed for the collapse that caused three deaths.

Perhaps the deadliest bridge collapse occurred in 1967. The Silver Bridge connecting West Virginia and Ohio gave way during rush hour and tumbled into the Ohio River, killing 46 people. The cause was eventually determined to be corrosion.

Steel corrosion on bridges is still a major concern. Infrastructure experts worry that thousands of American bridges are dangerously outdated and overburdened. In 2006, approximately one-fifth of interstate bridges were rated as deficient, either structurally deficient or obsolete.

Overall, one-quarter of all bridges in the U.S. are considered structurally deficient, and 80,000 bridges across the country need some sort of reconstruction or rebuilding.

Other recent bridge collapses include: