MBTA resumes Green Line Extension service after derailment

Train service resumed Thursday morning on the Green Line Extension, a day and a half after a derailment injured several passengers and triggered a federal investigation.

The T announced around 10:30 a.m. that regular service is once again running from North Station to Medford/Tufts and Union Square, the two endpoints on the Green Line Extension's branches, and that shuttle buses have been phased out.

Trolley service had been suspended since Tuesday afternoon, when a train came off the rails near Lechmere Station. About 50 passengers aboard were evacuated, and six were hospitalized with non-life-threatening injuries.

The National Transportation Safety Board sent investigators on Wednesday, and said a preliminary report should be ready within 30 days.

Gov. Maura Healey said Wednesday early indications suggest the derailment is "not attributable to the rail or the track," and that investigators are instead examining other factors such as the operator for a potential cause.