It has been determined through a federal investigation that load-bearing calculations were not done on the design of the Interstate Highway 35W Bridge in Minneapolis, Minnesota which collapsed on August 1, 2007 killing 13 people and injuring 145. The design firm used improperly sized steel plates in the design of the bridge attributing to the collapse the National Transportation Board noted in its final report. The report also put blame on the Minnesota and federal authorities for negligence because they did not properly review the design during inspections of damages to the plates that had occurred prior to the accident.
It is possible that even in the wake of this tragedy, the current state and federal design review processes may be unable to detect design flaws. In the report, the National Transportation Board proposed nine recommendations to the Federal Highway Administration and the American Association of State Highway and Transportation officials. The proposals included recommendations on improving training for bridge inspectors and strengthening government oversight of design contractors to catch problems before they lead to devastating accidents.