On This Day

Friday 15th December 1967

52 years ago

The Silver Bridge connecting Point Pleasant, West Virginia and Gallipolism Ohio (US), over the Ohio River, collapsed while full of rush-hour traffic. Dozens of cars fell into the icy water. Forty-six people lost their lives in the accident, and many others were injured. Two of the victims were never found. Investigation of the wreckage pointed to the cause of the collapse being the failure of a single eyebar in a suspension chain, due to a small defect 0.1 inch deep. Analysis showed that the bridge was carrying much heavier loads than it had originally been designed for and was poorly maintained. The collapse focused much needed attention on the condition of older bridges, leading to intensified inspection protocols and numerous eventual replacements. There were only two bridges built to a similar design, one upstream at St. Marys, West Virginia, and the notably longer Hercilio Luz Bridge at Florianópolis, Brazil. The St. Marys bridge was immediately closed to traffic and the bridge was demolished by the state in 1971. A small truss bridge was kept to allow access to an island in the river. The Hi Carpenter Memorial Bridge was later built to replace the demolished bridge. The Hercilio Luz Bridge remained in active service until 1991 and still stands at Florianópolis due to being built to a higher safety factor than the West Virginia bridge. Modern non-destructive testing methods allow some of the older bridges to remain in service where they are located on lightly traveled roads. Most heavily used bridges of this type have been replaced with modern bridges of various types.The collapse inspired legislation to ensure that older bridges were regularly inspected and maintained; however, aging infrastructure is still a problem in the United States. In 1983 the Mianus River Bridge in Greenwich, Connecticut, collapsed, causing the deaths of three drivers. The I-35W Mississippi River bridge disaster in 2007 resulted in 13 deaths. In early September 2009, the failure of an eyebar in the San Francisco–Oakland Bay Bridge was discovered during a scheduled closure, resulting in an emergency repair to reinforce the failed member. A memorial was installed in Point Pleasant to commemorate the 46 bridge collapse victims. The collapsed bridge was replaced by the Silver Memorial Bridge, which was completed in 1969.