An MBTA spokesperson said the train operator stopped the train after they spotted a downed wire in the tunnel.

Hundreds of passengers aboard the Blue Line were evacuated Tuesday afternoon after a train became stuck beneath the Boston Harbor, between the Maverick and Aquarium stations, officials said. Over the course of about an hour, Boston firefighters assisted with the evacuation of 500 people from the disabled train, the department said.

Around 500 MBTA riders were reportedly stuck on a Blue Line train Tuesday afternoon, according to officials. The train was disabled under the Boston Harbor between Maverick and Aquarium stations, the Boston Fire Department reported. It took firefighters about an hour to evacuate the 500 people through the tunnel.