An old railroad bridge collapsed Friday and several cars of a freight train dumped coal and small amounts chemicals into the Anacostia River.
No one was injured, and the oil and hydraulic fluid that spilled into the water were quickly contained, said Allan Etter, a D.C. Fire Department spokesman.
Investigators were not sure whether the derailment of ten cars or the collapse came first, said Bob Sullivan, a spokesman for CSX Transportation Inc.
The bridge is owned by the National Park Service and leased to CSX, which also owns the train and the tracks, Etter said. It had not been used in about a year, Sullivan said.
The Federal Rail Administration was investigating the cause of the accident, Etter said. Fire inspectors found the bridge to be in serious disrepair and not structurally sound, he said.
The 89-car train was being moved across the bridge to an indoor rail yard in southeast Washington when the cars jumped the tracks.
Two hours after the collapse, one coal hopper sat almost sideways across the bridge, while several others dangled into the water about 10 feet below. No other rail traffic in the area was affected.
CSX was sending contract workers to clean up the spilled coal and chemicals and to pull the remaining cars off the bridge and out of the water, said Sullivan.