NTSB: Signals failed before Metro crash

WASHINGTON - Investigators say signaling equipment that periodically failed may have caused last Monday's deadly Metro accident. There also is new information that raises questions about what Metro officials knew and when they knew it.

The collision killed nine people and injured nearly 80 when a moving train slammed into another train stopped on the tracks near the D.C.-Maryland state line. The cause of Metro's deadliest ever crash has yet to be determined.

Metro's signaling system is supposed to detect passing trains and transmit speed and stop commands. But the National Transportation Safety Board says problems began occurring after a piece of equipment was replaced June 17, five days before the crash.

"This is not an issue that would have been easily detectable to controllers in our operations control center," Catoe said in a statement.

A Metro spokesperson says the circuit that failed was tested immediately after installation, and it was working correctly at that moment. However, Metro says it had no knowledge the circuit was failing in the days before the crash.

Dave Kubicek, Metro's rail chief, says the electronic indicator that its signalling system was only working intermittently is so tiny, a controller in the operations center would have to be looking at the exact point at the exact time to catch the problem. He tells The Washington Post Metro didn't realize the system was flittering on and off in the days leading up to the crash. It was discovered after the accident when officials started examining data.

Before the crash, the signaling system was typically tested each month, Catoe said. Reviews are now being performed daily.

Metro Board Chairman Jim Graham tells WTOP that management should have known of the problem, but isn't sure whether equipment or human error is to blame.

"We're checking on this right now. We're not clear whether or not there was a red flag or not. There was a human being involved in this circuit on June 17. We're not sure whether or not what happened after was human error. We're trying to figure out what Metro should have known."

The NTSB also found the train detection system near the Fort Totten station on the Red Line continues to fail in testing that's taken place since the accident. Metro says that's why the trains are running at such slow speeds and thus the delays on the red lines.

As for safety, Metro spokeswoman Lisa Farbstein says, "The system can't get any safer."

The Associated Press contributed to this article.

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