ABC News, 1/29/15:
Passengers Claim to Have Smashed Boston Train Windows to Escape Smoke
Passengers on a Boston subway at Quincy Station this morning panicked and smashed windows to escape a smoke-filled Red line train, according to witnesses.
A nurse who was in the train at the time told ABC News she started smelling something like "burning rubber" while they were stopped at Quincy station.
Sounds like Boston is trying to do its best Washington impersonation. I believe however that the Quincy station is covered but open air on the ends, so there was a little more ventilation than L'Enfant Plaza had.