On February 18, 1981, about 4:10 p.m. eastern standard time, a tractor-semitrailer loaded with building supplies accelerated out of control while descending a steep 3-mile grade near Frostburg, Maryland. The combination vehicle was traveling eastbound on U.S. Route 40 when it passed and sideswiped a slower moving pickup truck in the eastbound lane. The combination vehicle then entered the city limits of Frostburg, Maryland, where it collided with eight vehicles and pushed them into six other vehicles. The semitrailer uncoupled and overturned, and the tractor pushed another vehicle with two occupants into a three-story commercial building before coming to rest. As a result, an explosion and fire erupted in the building. Three persons were killed, and the truckdriver and 11 vehicle occupants were injured. Property damage was estimated at more than $675,000.