Light-rail crash hurts 26 in Boston Boston Mayor Ray Flynn, right, watches workers clear debris after a collision between two underground light-rail trains at Boston's Arlington Station. At least 26 people who "went flying through the air" were injured. The Massachusetts Bay Transportation Authority police said one outbound two-car Green Line trolley rammed into the rear of another two-car trolley stopped in the station. The cause of the accident is under investigation. The collision was second underground train wreck in Boston this month. On Dec. 12 an Amtrak Night Owl train slammed into a commuter train in Boston's Back Bay Station, injuring more than 260 people.