Several injured when passenger train derails in Cambridge, Massachusetts

CAMBRIDGE - Seven people suffered minor injuries Tuesday evening after a Green Line train derailed near Lechmere Station in Cambridge, Massachusetts. The Massachusetts Bay Transportation Authority chief said the agency is focused on investigating "human factors" in the derailment, which still wasn't cleaned up as of early Wednesday morning.

Approximately 50 people were on board the train when it derailed after leaving Lechmere Station at about 5 p.m. local time.

MBTA Chief Operating Officer Ryan Coholan said the derailment happened at the Red Bridge interlocking, where the Medford/Tufts branch and Union branch intersect.

"While the train was traversing over that switch, the lead truck and the center truck of the leading Green Line trolley derailed," Coholan said.

Cambridge is a suburb of Boston.

All passengers evacuated themselves onto the tracks and walked to an emergency exit. The seven people who were taken to the hospital suffered minor injuries, according to the MBTA.

Investigation focused on "human factors"

The exact cause of the derailment is still under investigation. "Preliminary indications do rule out any issues with the track structure and right now we are focused on the human factors involved with this incident," Coholan said.

The National Transportation Safety Board said it is sending a team to investigate the incident.

Shuttle buses were replacing service between North Station and Medford/Tufts due to the derailment. Passengers can also use the 87 bus for alternate service.

"The MBTA sincerely apologizes to riders for the frustration and distress this incident has caused," the MBTA said in a statement. "We are committed to thoroughly investigating this matter to ensure this does not happen again."