POSTED: 10:58 pm EDT May 28, 2008
How safe is the public transit system that so many of us travel each day?
Team 5's Sean Kelly looked into the MBTA safety records and history of MBTA crashes.
Consider the fact that hundreds of thousands of people use MDTA commuter trains every week without problems and you'd have to say the safety record is very good.
Looking back at the history of accidents, however, it's typical for one train to be stopped when a crash occurs.
The Green Line has had more than its share of collisions over the last two decades.
One, in 1990, when one train rammed into the rear of another at the Arlington Street station, hurt 33 people, although there were no fatalities.
Investigators determined that the 64-year-old driver who caused it had a blood-alcohol level above the legal limit.
Five years later, another collision at the busy Copley Square station. Once again, a trolley rear-ended another car that had stopped. Thirty-two people were hurt but no one was killed.
The NTSB determined the female driver who caused it failed to follow posted speeds and never applied the brakes.
Until Wednesday’s Newton crash, the most recent serious collision involving passengers happened in March.
That's when a runaway freight car from a lumberyard slammed head-on into a commuter train in Canton.
It had by far the highest number of casualties at 150, although most injuries were minor.
MBTA investigators determined the driver likely saved lives by halting his train to avoid a bigger crash.
As bad as all of those collisions were, none matched what MBTA passengers saw in January 2007.
Their commuter train traveling through Woburn, Mass., hit and killed two track workers.
NTSB investigators determined a dispatcher forgot about the work crew and failed to warn the driver.
Two Massachusetts Bay Transportation Authority (MBTA) Green Line trains have collided in Newton. Both trains consisted of two cars, one of which rear-ended the other causing major damage on both trains, multiple injuries and trapped the female operator of one of the two trains, 24 year-old Terrese Edmonds, who subsequently died. An investigation by the National Transportation Safety Board is underway.
Green Line D train 
The crash happened yesterday around 6 p.m. EDT between the Waban and Woodland Green Line stations on the Green Line's D Branch. One train was stopped at a red signal waiting to enter to Woodland when it was struck from behind by the second train. 

According to MBTA spokesman Joe Pesaturo, "The first one was stopped at a red signal and was ready to proceed to the station when it was struck."

The Green Line, which is the most heavily used light rail line in the United States, is made up of four branches. The D Branch runs along a dedicated right of way and the stations are more spaced out as opposed to the other branches which run on the street. 

This is one of several accidents the MBTA has experienced recently. Exactly two weeks ago, a trolley on the B Branch derailed and caught fire, and Tuesday, a fire broke out between Park Street and Downtown Crossing on the MBTA's Red Line. The MBTA's Commuter Rail division has also experienced accidents including the death of a 5-year old in Revere who was stuck by a commuter train in the middle of a grade crossing this Tuesday and a MBTA commuter train that was rear-ended by a runaway boxcar belonging to CSX back in late March. Quick thinking on behalf of the engineer on that train is believed to have averted a larger accident.