JEFFERSON COUNTY, N.Y. (WSYR-TV) — A deadly tractor trailer rollover crash happened on State Route 37 just north of the hamlet of Redwood in the town of Alexandria, in Jefferson County, according to State Police.

Photo provided by New York State Police

New York State Police, Redwood Fire Department and Alexandria Bay Fire Department, and Ambulance arrived at the scene around 5:53 a.m.

After investigation, they found that the driver was heading south on State Route 37 when he possibly suffered a medical event prior to exiting the right shoulder of the road.

The driver of the tractor trailer was treated immediately at the scene and then taken to River Hospital, where he was pronounced dead.

This investigation is ongoing and Troopers say the name of the driver is pending next-of-kin notification.