It's not usually a good sign when smoke starts pouring out of a trolley, as Emily shows us around 4:40 p.m.
She reports the train was evacuated. Brookline FD showed up and took care of whatever was causing the smoke and the T made preparations to have the train towed away (and shot?) so that service could resume.
Not long after, passengers had to get off an inbound Orange Line train at Mass. Ave. due to brake issues.