An elderly man was killed this morning after he tumbled into the railroad tracks in Little Neck this morning, and was hit by an LIRR train, authorities said.

He fell about 10:20 a.m. at a railroad crossing near 39th Road and Little Neck Parkway, and was struck by an eastbound Port Washington train.

He went into cardiac arrest, and was pronounced dead at the scene, according to an FDNY spokesman.

Service was suspended on the Port Washington line for 90 minutes after he fell, said a MTA police spokesman.

He has not been identified yet, but is believed to be in his seventies, authorities added.