Eleven firefighters were burned, six seriously, one critically, and one extremely critically, in an explosion that occurred while they were attempting to extinguish a sodium fire in a metals processing establishment in Newton, Massachusetts on October 25, 1993. The incident illustrates how quickly and unpredictably an apparently minor hazardous materials situation can change, with tragic consequences. It also shows how standard protective clothing and equipment, designed for structural fire fighting, is dangerously inadequate for a molten metals incident. The situation was caused by a deviation from standard procedures for handling waste sodium at the facility. The incident provides an important series of lessons for all firefighters on the risks involved with sodium and other flammable metals and on the need to obtain reliable information from responsible individuals at hazardous materials incidents.