Green Line service resumed Thursday between North Station and Medford/Tufts following the closure after a derailment Tuesday.

“Regular service has resumed between North Station and Medford/Tufts & Union Sq,” the MBTA posted on X, formerly Twitter, Thursday morning. “Shuttle buses have been phased out.”

The entire Green Line extension branch was replaced by shuttle buses Tuesday afternoon and Wednesday while officials investigated an incident in which a train went off the rails near Lechmere station in Cambridge.

Around 5 p.m. Tuesday, MBTA officials reported, a Green Line car came off the tracks but remained upright, sending seven passengers to the hospital with “minor injuries.”  Ryan Coholan, MBTA Chief Operating Officer, told reporters Tuesday that preliminary findings led investigators to look at “human factors involved.”

The National Transit Safety Board said they were actively investigating the incident and on site Wednesday.

T officials said they would make repairs and restore service “once the investigation is complete and the area is returned to the T” on Wednesday.