Why she didn't take the Orange Line home today

Jennifer Stewart was on the Orange Line headed toward Back Bay today, when she heard two loud bangs and then the lights flickered on and off and the train just stopped:

... I turned my head to the left, as if there was a snowball's chance in hell of me seeing anything that would explain the commotion, and saw....smoke.

Yep, smoke. Billowing up outside the window of the doors next to which I was sitting. And then smoke curling into the car itself through the crack at the top of the doors. Oh goody. And then the screaming (or, more appropriately, as it was supplied almost entirely by a pack of teenaged girls, shrieking) started. ...