On June 30, 1992, a Burlington Northern Railroad freight train derailed on a bridge over the Nemadji River at the southern edge of town of Superior, Wisconsin. The derailment resulted in a liquid benzene spill into the river. The fumes from the spill led to an evacuation of an estimated 80,000 residents from the town of Superior, the city of Superior and Duluth, Minnesota, apparently the largest evacuation in U.S. history resulting from a train accident.