By CBSBoston.com StaffApril 14, 2022 at 6:13 pm BOSTON (CBS) – NTSB investigators have completed the on-scene portion of their investigation into a deadly accident on the MBTA’s Red Line. Last weekend, 39-year-old Robinson Lalin died after his arm got trapped in a train door. The Suffolk District Attorney’s Office said Lalin got his arm stuck in the door of the inbound train as it pulled away from the platform at the Broadway station in South Boston around 12:30 a.m. Sunday.