Leaving work from EWR tonight about 1930, saw a CO B-737 parked away from the terminal (C) on the taxiway.

There were at least 15 "emergency services" vehicles surrounding this aircraft. There were also 2 buses alongside the aircraft. The main cabin door was open and there were stairs brought up to the doorway. I saw no people moving around either outside or inside the aircraft.

Okay, so that is what I saw. Who knows what about this?

Thanks...