Sleep disorder likely factor in trolley crash

WASHINGTON — A federal safety panel said Tuesday that the trolley operator who died after her train rammed another trolley in a Boston crash last year had ignored a red stop signal, likely because she suffered from an undiagnosed sleep disorder that caused her to briefly fall asleep.

The finding came in the National Transportation Safety Board’s final report on the May 2008 collision in suburban Newton, Mass. that also injured seven passengers on the Massachusetts Bay Transportation Authority’s Green Line.

Testing showed the presence of doxylamine — which is used in over-the-counter sleeping aids — in operator Terres Edmonds’ urine. The safety panel said Edmonds had a high body mass index, which is closely correlated with a higher risk for sleep apnea. Sleep apnea can cause problems sleeping at night and drowsiness during the day.

“The operator of the striking train was at a high risk for having undiagnosed sleep apnea, and she may have been chronically fatigued as a result of the condition,” the safety board concluded.

The panel also said the fatal crash could have been prevented if the MBTA had used an automated train control system.

Acting NTSB Chairman Mark V. Rosenker said if such a braking system had been implemented, “I don’t believe we’d be here discussing this today.”

Rosenker noted that other MBTA lines had such systems.

“If technology exists and it exists on the other lines, why would the Green Line not have everything possible that is going to prevent the accidents from happening?” Rosenker said.

MBTA spokesman Joe Pesaturo said no safety system is perfect, citing the recent fatal crash on the Metro system in Washington, D.C.

“They have this (automated) system in DC and last month they had an accident in which nine people were killed,” he said. “It’s not a fail-safe system.”

The Metro has since switched to a manual system, similar to that used on the Green Line, he said.

Pesaturo said the MBTA will test a new trolley collision-avoidance system that relies on radio waves to alert drivers as they approach another train. If the driver fails to act, the system automatically stops the train.

Massachusetts Gov. Deval Patrick said an autobraking system is “something I’ve been interested in a long time.”

He also expressed more general safety concerns at the MBTA, citing the crash that killed Edmonds and another this May caused by a driver authorities say had been text-messaging.

Edmonds, 24, should have halted her trolley for one minute and continued slowly at 10 mph because the signal was red, indicating a train ahead, NTSB investigators found.

Instead, her trolley plowed into another train. Investigators estimated the striking trolley was moving at 38 mph at impact.

The trolley struck from behind had stopped at a second red signal that had been malfunctioning intermittently, investigators said.

Investigators found broken electrical connections between track sections, interrupting the signal that would have made the second signal light go on and off correctly.

Operators were not required to report faulty signals by the MBTA, a factor that likely contributed to the accident, investigators said.

“This could lead to a great safety risk,” investigator Jeff Leaman told the panel.

The crash damage was estimated at $8.6 million. About 185 to 200 passengers were on the two trains when the crash occurred.

Investigators told the panel that testing showed that no illegal drugs or alcohol were detected in the operator’s system when she died.

On the Net:

National Transportation Safety Board: www.ntsb.gov

Associated Press writers Steve LeBlanc and Glen Johnson contributed to this story from Boston.