The incident took place in Mount Sinai around 10:55 p.m., Thursday, Nov. 3, on County Road 83.
According to Suffolk County Police, Ann Marie Montgomery, age 42, of Holtsville, was walking westbound on northbound County Road 83, north of Canal Road, when she was struck in the left lane by a 2018 Ford F150, driven by James Gerardi.
Montgomery was pronounced dead at the scene by a physician from Port Jefferson EMS, police said.
Gerardi, age 57, of Mount Sinai, was not injured.
The Ford was impounded for a safety check.
Detectives are asking anyone with information on the crash to contact the Sixth Squad at 631-854-8652.
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