The dead man’s switch saved a G train full of passengers today when the subway motorman died of a heart attack while on the job.

The subway pulled out of it’s terminal at Court Square today at 8:08 a.m., and the motorman was struck by the attack just after.

Once he released his grip from the handle on the control panel, the train stopped as if someone pulled the emergency brake.

The train can’t move unless the handle is compressed. On newer cars, the motorman has to hold down a bar with his foot, and on the L line, the operator must press a button every 30 seconds.

When the train stopped, the conductor went to investigate and found the operator unconscious and “radioed the Rail Control Center for medical assistance,” the MTA said.

“A Train Service Supervisor moved the train back into the station to allow medical personnel to treat the Train Operator. The Train Operator was removed by EMS to Elmhurst Hospital, and was pronounced dead at 9:20 a.m.” the agency said.

(Source: NY Post)