Officials said a person who was driving a Chevy Tahoe had a medical condition around 1 p.m., which caused them to lose control of the vehicle. A tractor trailer subsequently hit the Tahoe from behind.
One adult and three children from the Tahoe were transported to Duke with non-life-threaten injuries. The driver of the tractor-trailer was treated at the scene.
Eyewitness video shows the aftermath of the crash.
Tractor-trailer crash closes I-85 near Hillsborough
The accident was said to have happened near mile marker 165.
Authorities say neither drugs nor alcohol were a factor in the crash, and no charges have been filed.