Final analysis of '08 Green Line crash due Tuesday

While no officials would detail a cause Monday, documents and prior statements from investigators suggest driver error was the primary reason.

"It threw me out of the seat at first, but then I landed in the seat, and then I jumped up, and I hit my mushroom, which is the emergency brake, three times," Jenness said. "It wasn’t stopping."

Jenness's trolley had been stopped at what investigators believe was a signal that was stuck on red just west of the Waban station. The trolley had just started moving at the time of the crash. The driver of the trolley, seated in the front car, reacted to the red signal properly, stopping for a minute and then moving forward at no more than 10 mph.

Tests later showed connections on the track that conduct electricity were rusted, which probably caused the signal to default to the red position, according to the report.

The trolley behind, driven by Edmonds, encountered a second red signal, requiring it to stop so it would not hit Jenness's trolley. But Edmonds did not stop, according to crash records. She proceeded through the signal at 38 mph, causing the violent rear-end colission.

Spokesmen for the NTSB and the Massachusetts Bay Transportation Authority declined to comment before tomorrow's release of the final safety recommendations.

Read a fuller account of the trolley operator and another witness here. See a photo slide show of the trolley cars here.

It remains unclear why Edmonds ignored her red signal. The records released yesterday say there were no illegal drugs or alcohol found in her system when she died. There was, however, the presence of Doxylamine, often included in over-the-counter sleep medication, in Edmonds’s urine.

Investigators did not say in the initial report whether they believed that was a factor. However, the drug, found in medicines such as Unisom and some versions of NyQuil, can leave people “sluggish” even a day after taking them, said Candy Tsourounis, a professor of clinical pharmacy at the University of California, San Francisco.

“With most over-the-counter medicines, you will see some drowsiness eight, 10, 12 hours after the dose,” Tsourounis said.

Drugs containing the product customarily include a warning about operating heavy machinery.
The crash that killed Edmonds also injured seven other passengers, one of them critically.

Damage was estimated at $8.6 million to the trolleys involved in the crash.

The NTSB is also investigating a second Green Line rear-end crash near Government Center that occurred May 8 of this year. In that crash, an operator told authorities he was writing a text message to his girlfriend in the moments before impact.

Though both crashes seem to be the result of operator error, the MBTA’s antiquated signal system has been criticized for its lack of an automated crash-prevention system. The NTSB is expected to discuss that issue in its report today.

Other lines and other systems across the country have automated systems designed to prevent trains and trolleys from coming too close to one another.