It happened on Monday, Dec. 7 at approximately 11:25 a.m. in Selden.
John Swanson, 75, of Riverhead, was driving westbound on Route 25 in Selden when his 2019 Chevrolet van jumped the curb and struck a 1997 Dodge pickup truck and a parked vehicle on North Bicycle Path, Suffolk County Police said.
Detectives believe Swanson may have suffered a medical event while driving, said police.
He was transported to Stony Brook University Hospital where he was pronounced dead.
The two male occupants of the Dodge were not injured.
The Chevrolet and Dodge were impounded for safety checks.
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