At 10:11 a.m. on May 15, 1985, a New York City Transit, Authority Southbound eight-car subway train derailed moments after departing the DeKalb Avenue Station, Brooklyn, New York. The train had made a station stop, proceeded out of the station, and then entered a track crossover section. The first car entered the crossover, but the second car derailed at the left-hand switch, continued in a derailed condition for about 120 feet, and struck a concrete-and-steel track separation wall. The right side of the derailed car struck the wall at the unoccupied conductor's cab and severed 20 feet of the car side. The third rail was damaged for approximately 40 feet, and the third-rail wooden cover board was forced up under the derailed car. Dense smoke resulted when arcing of the damaged third rail caused a fire in the cover board and the wiring insulation on the car.
An attempt was made to restore rail service on the tracks not involved in the accident, 1 hour 7 minutes after the derailment by restoring the third-rail power to the northbound tracks. However, a series of explosions occurred under the derailed car when the third rail at the accident site became energized. Forty-nine passengers and 7 employees were treated for smoke inhalation by the emergency medical services, and 16 passengers were treated at local hospitals. Damage was estimated to be $400,000.