CBS LocalMBTA Trolleys Collide In Dorchester, 7 HurtCBS LocalEmergency workers at the trolley collision in Dorchester Wednesday morning. (Photo credit: Chris McKinnon-WBZ-TV). Related Tags: Ashmont, Butler Street, CBS Boston, Chris McKinnon, Dorchester, Mattapan Line, MBTA, Trolley Collision, WBZ ...Boston trolleys make contact; 7 reported hurtseattlepi.com7 Injured in 2-Trolley CollisionNECNall 7 news articles »