Crews were responding to reports of a power outage when they found 21-year old Brian McClellen of Cleveland on fire on a train heading from Greenwich to Grand Central Terminal.
The MTA said that investigators spoke with McClellen before he died from his injuries on Monday and determined he was not train surfing or trying to do a stunt. The agency would not say why he was up there.
The fire was extinguished and McClellan, an actor and model, was taken to Westchester Medical Center, where he died.
MTA police are investigating how McClellan got on top of the train, and whether he struck the overhead electrical wires that power the trains.
The train was carrying about 20 passengers.