When I got on on the second car of an inbound trolley at Hynes early this afternoon, it was fairly crowded, and the back half of the car was packed with high-school kids.
About halfway between Arlington and Boylston, WHAM, the train slammed to a stop. Some guy began yelling "Is everybody OK?" The operator got on the PA and asked the same question. Everybody was. And then the operator got back on and said "You kids back there better stop fooling around, somebody's going to get hurt."