Every subway train comes equipped with a dead man’s switch. As seen in The Taking of Pelham 1-2-3, this is a handle the train operator must keep depressed while the train is in motion. If he lets go — if something happens or the driver becomes incapacitated — the train will stop. This week, along the G train, Domenick Occhiogrosso, 50, pulled his train out of Long Island City and suffered a fatal heart attack while the train was in motion. His death triggered the dead man’s switch, and the train came to a stop. The conductor discovered Occhogrosso unconscious in the booth, and he was pronounced dead at 9:20 a.m. yesterday morning.