A 20-year-old motorcyclist was killed in a crash Sunday morning in Westbury, Nassau police said.

Nicholas Cartier, of East Farmingdale, was driving a 1999 Yamaha motorcycle westbound on Union Avenue when he “passed a steady red traffic signal” and struck a flatbed truck that was traveling southbound on Grand Boulevard at about 8:34 a.m., police said in a news release.

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Cartier was taken to Nassau University Medical Center in East Meadow, where he was pronounced dead by hospital staff at 9:19 a.m., police said. The 51-year-old male driver of the flatbed truck was not injured, police said.

Both vehicles have been impounded for brake and safety checks, police said.

The investigation is ongoing.