Bridge Inspections and Collapses

Bridge Inspections are a priority! Millions of people cross bridges daily. These bridges are inspected by trained engineers, but sometimes damages occur, or problems are unnoticed leading to bridge collapses. Over the last 50 years, there have been several U.S. bridges collapsed. Some of these were caused by accidents or collisions while others are structural deficiencies. Here are some examples of major U.S. bridge disasters:

• As an example, the Hyatt Regency Walkway in Kansas City, Missouri, collapsed on July 17, 1981, killing 114 people. The weight of the guests caused the fourth and second-floor walkways to collapse. They both fell onto a crowded dance floor in the hotel lobby.
• Just outside Mobile, Alabama, on September 22, 1993, a section of an Amtrak passenger train fell from a trestle into the bayou and caught fire. A barge hit the railroad bridge just before the Amtrak train hit the bent tracks and then fell into the bayou. There were 47 deaths in the Big Bayou Canot accident.

• On December 15, 1967, the Silver Bridge collapse led to 46 deaths. The bridge reached from Point Pleasant, West Virginia, to Gallipolis, Ohio. Witnesses said the 1,460-foot bridge that was suspended fell into the river in less than 20 seconds. Investigators determined a bridge fracture caused the structure to fall like a “deck of cards.”
• In more recent years, in 2007, the I-35 W Bridge in Minneapolis, Minnesota, collapsed into the Mississippi River and killed 13 people. Investigators believe the bridge fell because the support plates were about half as thick as they needed to be.

Bridge Inspections

Bridge inspectors must undergo extensive training. There are guidelines regarding the frequency of bridge inspections, which depend on state and federal guidelines. The regulations establish the requirements for a bridge inspector, the required frequency of inspections, and the kinds of bridges that must be inspected. State Departments of Transportation (DOTs) usually adhere to the federal inspection regulations, which are found under the National Bridge Inventory Standards (NBIS) and will add to them. States usually require more frequent inspections than the NBIS calls for. To become employed as a bridge inspector, you must undergo specialized hands-on training and become familiar with NBIS and the state requirements.