Technology is supposed to prevent the sort of catastrophic crash that occurred Monday on Washington’s heralded subway system. As investigators began sifting through the twisted metal wreckage, the alert system designed to warn when Metro trains get too close and the initial call summoning rescue help emerged as two early subjects of inquiry.
Fire officials stated bluntly Monday night that Metro’s original description of the accident understated its magnitude, and it was only when the first rescuers arrived at the scene that the sort of help needed was finally summoned.
“A little after five o’clock we responded to what was believed to be a small incident,” D.C. Fire Chief Dennis L. Rubin said. “The first arriving company recognized the fact that apparently two trains had collided.” Fire officials eventually sounded three alarms, summoning hundreds of rescuers and implementing their mass- casualty operations.
A Metro press release issued shortly after 5:30 p.m. Monday incorrectly said the accident occurred after a train headed out of the city derailed on the Red Line. Officials later said a six-car Red Line train headed into the city stopped to wait for a third train to clear the platform at the Fort Totten station and was slammed into by another train from behind shortly after 5 p.m.
Authorities remained at a loss to explain the origins of the deadliest crash in Metrorail’s 33-year history Monday night. Federal investigators vowed to explore every potential cause of the accident that killed at least nine and injured more than 70: from train and track maintenance to operator training and equipment failures.
Experts focused their immediate attention on a system that is supposed to alert a train if it is approaching another.
Barry M. Sweedler, a former National Transportation Safety Board investigator and senior manager who now works for the consulting firm Safety and Policy Analysis International, said the trains should have had a system in place to bring the train to a stop if another is in its path.
“I believe that will be one of the major areas the NTSB will be looking at. Was it defective, was it overridden by the dispatcher or the operator?” Mr. Sweedler said. “The system is supposed to be in place; but if you’re operating in some kind of manual mode, there may be some instances where the system could be disabled.
“Much of this is probably recorded someplace, so they’ll try to piece it together, they’ll try to re-create the crash, just to get an idea of sight distance, what the signals showed, what the operator may have seen,” Mr. Sweedler added.
Jackie Jeter, head of the union that represents most Metro employees, including train operators, said the system to stop the train is called “automatic train protection.”
“What happens is that once you get too close, you lose your speed command, and when you lose your speed command, the train’s going to stop,” said Mrs. Jeter, who would not speculate on an exact cause of the crash. “There are a lot of questions, because there are a lot of relays on a train that are supposed to prohibit this type of thing from happening.”
Metro General Manger John B. Catoe Jr. acknowledged the agency has an alert system and said investigators would be looking into why the train may have run through “whatever signals that might have been coming.”
He said operators also are instructed to run their trains automatically during peak hours, but could not say whether the train involved in Monday’s crash had been running on automatic or manual operation.