UPDATED with MBTA statement about what the thing was. Also, Back Bay station was re-opened shortly after 2 p.m.
A ceiling drain pipe fell on the roof of an inbound Orange Line train at Back Bay around 12:25 p.m. No injuries, but passengers were briefly ordered held in the train. Needless to say, inbound service from Forest Hills is now at a standstill. The T is starting up a bus shuttle between Jackson Square and Back Bay.