Hazell Stoudemire, the older brother of NBA star Amar'e Stoudemire, died early this morning in a car accident in Florida ... TMZ has learned.

The accident happened on Route 27 in Lake Wales. According to the Florida Highway Patrol, Stoudemire was driving at a "high rate of speed" when he collided with the rear of a tractor trailer.

He died on the scene.

The Florida Highway Patrol says 35-year-old Stoudemire was not wearing a seat belt when he smashed into the big rig ... and they are unsure if alcohol was a factor.