Albert Pierro, 89, was driving a 2005 Honda north on Route 112 at about 6:40 a.m. when he struck the back of a 2009 Peterbilt that was going to make a left turn into PK Metals at 3542 Route 112.
The driver of the tractor trailer, Nikolaos Karoutsos, 29, of Port Jefferson Station, was not injured.
The crash closed Route 112 in both directions between Granny Road and Paul's Path for several hours; the road has since reopened.
Detectives ask anyone with information on the crash to call the Sixth Squad at 631-854-8652.
With Gary Dymski