A witness has told police that a Long Island Rail Road engineer let a passenger operate a train bound for New York City.

MTA Police Chief Michael Coan says the train ran smoothly and no one was injured.

The witness told police that he saw a passenger in the cab without the engineer during part of the run on July 2.

The double-decker train left Port Jefferson at 6:45 a.m. It normally has about 400 passengers and goes up to 80 mph.

The railroad calls the allegations "extremely serious and troubling."

MTA police are trying to find the passenger who allegedly operated the train. Coan says he doesn't think the engineer knew the person's name.

The Nassau County district attorney is investigating.

The engineer has been suspended.