An arcing third rail continued being supplied with power for more than 30 minutes after smoke in a Metro tunnel was reported in Monday's fatal malfunction, the National Transportation Safety Board revealed in a preliminary report released Friday afternoon.
The NTSB report provides details and chronology about the malfunction near the L'Enfant Plaza station but does not address the emergency response. D.C. Mayor Muriel Bowser promised Thursday a preliminary report on the city's response to the incident within 48 hours.
An electrical breaker tripped at one end of a section of the third rail at 3:06 p.m., but the breaker at the other end of the section remained closed and continued to power the rail until a remote command to open it was sent about 3:50 p.m.
First responders couldn't safely leave the Metro platform because they weren't told whether someone could be electrocuted by the third rail that powers the trains, authorities have said.
About 3:15 p.m. Monday, a Virginia-bound Yellow Line train left the southeast D.C. station -- one of the system's busiest -- but stopped 386 feet after the platform because of electrical arcing of the high-voltage third rail about 1,100 feet beyond the train. At 3:25 p.m., a following train stopped 100 feet short of the south end of the platform.
Passengers on both trains and the station's platforms were exposed to heavy smoke.
Metro activated ventilation fans at 3:16 p.m. to try to clear smoke, according to the NTSB.
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NTSB investigators found severe electrical arcing damage to the third rail and electrical cables. Arcing occurs when electricity from the rail has contact with another substance that conducts electricity.
"The third rail is high-voltage direct current, and if that current starts arcing to another conductor that it is not designed to connect with, you get a flash," NTSB investigator Michael Flanigon said Monday night. "In certain cases, that arc can start sort of feeding on itself, and it actually generates gases that are more conductive."
The tunnel and train filled with thick black smoke, and riders said they were trapped in the tunnel for at least 30 minutes before they were rescued. Jonathan Rogers recorded video and took photos of the incident with his phone, and according to the time stamps on his phone, the first plumes of smoke entered the train at 3:20 p.m. Rogers reported first seeing a firefighter enter the train at 4:20 p.m.
First-responding firefighters saw no civilians in the station, but four Metro Transit Police officers at the tunnel directed them to the stopped train carrying passengers in the tunnel, sources said. The crew told the officers power needed to be cut off, and the firefighters continued into the tunnel after an officer on a phone said it was, sources said.
In the tunnel, the firefighters couldn’t see the train’s taillights until they were right next to the rear of the train, sources said. The last car of the train was just as thick with smoke as the tunnel.
The firefighters asked passengers to open the door, but they couldn’t. That car, like three more on the six-car train, was 3000 series, which require two screws to be loosened before opening manually, sources said. The door was opened from outside with a Metro barrel key.
Once on the train, one firefighter set up triage while the others assisted passengers off the train and to the platform. Reinforcements arrived after about 10 minutes, sources said. In the meantime, firefighters carried one unconscious woman out. She had a pulse when she was found, but not when they got her outside the station, sources said, and they began CPR.
The first-responders also reported having no radio communication in the tunnel, sources said.
A preliminary timeline released Thursday said the first report of trouble came at 3:18 p.m., when a 911 caller reported seeing smoke emerging from a tunnel. That was one of several emergency calls that initially had D.C. Fire and EMS units dispatched to three locations.
Passengers said the train operator told them every three or four minutes to stay put and that the problems were temporary, but aside from several lurches, the train didn't move, though the operator told them he planned to return to the station, and the smoke only got thicker. Passengers lowered themselves to the floor to breathe.
One passenger, 61-year-old Carol Inman Glover, slumped to the floor unconscious near the front of the train, where the smoke was heaviest. Rogers said he and two other passengers tried for 20 minutes to revive her with chest compression and mouth-to-mouth. Someone tried to take her pulse but couldn’t find it. A man scooped Glover up in his arms and carried her through the cars toward the back of the train, Rogers said.
By 3:45 p.m., two people were still calling from the train to ask if help was on the way, the Associated Press reported. The first firefighters are believed to have reached the train three minutes later, deputy city administrator Kevin Donahue said Thursday.
At 4:09 p.m., officials reported performing CPR on Glover, who later died. She was taken to a hospital at 4:25 p.m.
The Office of the Chief Medical Examiner ruled Glover's death accidental by acute respiratory failure from smoke exposure.
Eighty-six other people were hospitalized, two in critical condition. More than 200 people were evaluated.
Glover, of Alexandria, was a mother of two sons and a grandmother of one granddaughter. She worked at DKW Communications Inc. for the past 18 months, and won the award just last month. She rode Metro to her job daily.
She was the first passenger to die in the Metro system since a 2009 crash that killed eight passengers and a train operator.
Several Metro passengers injured Monday announced Thursday the filing of a lawsuit against the transit agency for negligence.
Smoke and fire occur, on average, almost twice per week on the aging subway system, which opened in 1976 and still uses some original rail cars. Metro's most recent quarterly safety report showed 86 incidents of smoke or fire in 2013 and 85 such incidents through the first eight months of 2014.
