Smoke appears in Washington subway system three times in two days, Cause Remains MysteryA mechanical failure on a Washington subway train caused smoke to fill a station stop on Sunday in the nation’s capital, the third such incident in two days, according to officials. L’Enfant Plaza station briefly filled with smoke after a mechanical issue occurred around 11 a.m., Metro spokesman Dan Stessel said. He said officials were looking to see whether the failure was connected to a recent bout of wintry weather. On Saturday evening, firefighters responded to a report of smoke and fire on a train line connecting Washington’s Foggy Bottom station to a stop in Rosslyn, Virginia. The fire was caused by problems with system’s electrified third rail, Stessel said. Earlier on Saturday, around noon, passengers riding another train were evacuated after faulty brakes caused smoke to fill Woodley Park Metro station, officials said. No injuries were reported during the incidents. MORE