Police say a man was found dead underground in a sump off the Long Island Expressway in Old Westbury Tuesday morning.

According detectives, the Old Westbury Police Department located an unoccupied vehicle parked eastbound on the south service road, west of exit 39 near a sump.

Police requested assistance from the Nassau County Police Departments Emergency Services Unit and Marine Bureau.

Marine Bureau performed a diver search of the sump.

Police say they located a white male, 73, who was submerged in the sump. The male was pronounced at scene by a Nassau County Police Medic.

There is no criminality at this time. The death is undetermined in nature.