A transit worker at the controls of a moving G train died this morning from an apparent heart attack. A spokesperson with New York City Transit says the train was pulling out of the Court Square station in Queens when the motorman collapsed. The train stopped immediately, because of what's known as the "dead man's switch." It's a handle on the control board that the motorman needs to hold down in order to keep the train moving. No one else was injured. The motorman's name was not released, pending notification of his family.