It happened around 10:15 p.m. Sunday, May 26, in Shirley.
Suffolk County Police said the man was driving a 2015 Infiniti Q50 southbound on William Floyd Parkway, just north of Robinwood Drive, when he lost control of the car.
The vehicle struck a metal guardrail and overturned multiple times.
The victim, Iran Palmer, age 38, of Farmingville, was pronounced dead at the scene by a physician assistant from the Office of the Suffolk County Medical Examiner.
He was the vehicle's sole occupant at the time of the crash.
Detectives are asking anyone with information on the crash to contact the Suffolk County PD Seventh Squad at 631-852-8752.
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