It happened around 1:50 a.m. Tuesday, Aug. 20, in North Bellport.
The victim was walking in the right lane of westbound Sunrise Highway (Route 27), east of Exit 55, when she was struck by a 2015 Kenworth tractor-trailer, according to Suffolk County Police.
Maureen Howley, age 77, of Bellport, was transported to Long Island Community Hospital in Patchogue, where she was pronounced dead.
The tractor-trailer driver, a 30-year-old East Hampton woman, was not injured.
Motor Carrier Safety Section officers performed a safety check of the Kenworth at the scene.
Detectives are asking anyone with information on this incident to call the Fifth Squad at 631-854-8552.
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