the number six and eight cars, and an engaged parking brake on the number nine car. After clearing the derail bar circuits and manually releasing the parking brake, No. 363 was cleared to proceed, and upon reaching the end of the line in Daly City, was taken out of service for inspection. A line switchbox cover had fallen off No. 363 and was resting on the third rail, which was not seen by following trains until it jammed against the third rail coverboard, breaking the collector shoe on No. 117, which caused a short circuit and electrical arcing. The train following No. 363 was dispatched to run in "road manual" mode, where the train is controlled by the onboard operator, rather than by the computerized central control system. That train reported seeing derail bar debris between the tracks near where No. 363 had stopped, but that the tracks were clear and available for service. The train immediately following also ran in "road manual," but subsequent trains were dispatched through the tube in automatic mode, including seven-car No. 117, the tenth train to enter the westbound tube after No. 363; No. 117 had 40 passengers onboard. Response No. 117 came to an emergency stop at 6:06 p.m., about into the Transbay Tube, with the operator reporting thick smoke coming from his train. The collector shoe assemblies on the number five and six cars of No. 117 had broken after striking the line switchbox cover which had fallen off No. 363 and jammed into the cover of the third rail. The NTSB later concluded the resulting electrical arcing between the train and the energized third rail ignited components on the car, causing air tanks and suspension airbags to explode on the fifth and sixth cars. Central operations shut down power to the third rail, but restored it 40 seconds later in an effort to uncouple the lead portion of the train from the burning cars. This was unsuccessful, and vent fans were turned on at 6:08 p.m. to attempt to clear the smoke, and the third rail was again powered down at 6:15 p.m. A BART line supervisor who had been riding on the train helped gather passengers in the lead car, including one blind passenger. BART central dispatch attempted to call the Oakland Fire Department, but unintentionally called San Francisco instead at 6:09 p.m. The Oakland Fire Department responded to the