The incident took place in Ronkonkoma around 8 p.m., Monday, Dec. 5.
Suffolk County Police Major Case Unit detectives report the man, identified as Robert Twiford, age 61, of Melville, was lying in the roadway of the LIE Exit 60E off-ramp when he was struck by at least one vehicle, which then fled the scene.
Twiford was transported to Stony Brook University Hospital where he was pronounced dead, police said.
Anyone with information on the crash is asked to call Major Case Unit Detectives at 631-852-6553 or Crime Stoppers at 800-220-TIPS.
All calls will remain confidential.
Click here to follow Daily Voice Brentwood and receive free news updates.