A trespasser on the railroad tracks was struck by an eastbound LIRR train arriving at the Port Jefferson station just before Wednesday's afternoon rush hour, railroad officials said.
Service between Stony Brook and Port Jefferson was restored just before 4:45 p.m., about 90 minutes after the person was struck, a spokesman said.
A double-decker diesel train hit the person near Bayliss Avenue, just west of the station and the Route 112 crossing, said spokesman Salvatore Arena for the Long Island Rail Road.
A representative with the Port Jefferson fire department said it transported the person, who was alive, to a hospital.
Buses had been dispatched to stations in Stony Brook and Port Jefferson Station, Arena said.
Other details were not immediately available.
Earlier Wednesday, a Holbrook man was struck and killed by a train west of the Ronkonkoma station, Arena said.
The man was not authorized to be on the tracks and was hit at about 2:45 a.m. near Ocean Avenue, just west of the station, Arena said.