A 33-year-old man from Brentwood was driving a 2017 Jeep Grand Cherokee northbound on Joshuas Path, near Stonehenge Lane.
He attempted to make a right-hand turn into a parking lot and was struck by a 2016 Yamaha motorcycle that was trying to go around the Jeep, according to Suffolk County Police.
The driver of the motorcycle, a Centereach resident, age 33, was rushed to South Shore University Hospital in Bay Shore with serious injuries.
The driver of the Jeep was not injured.
Anyone with information on the crash is asked to contact Fourth Squad detectives at 631-854-8452.
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