A truck carrying rags soaked in paint thinner spontaneously combusted on U.S. Interstate 20 early Friday morning, blocking an off-ramp and causing school authorities to close the Georgia Perimeter College Newton campus for the day.

According to Newton County Fire Department Deputy Chief Tim Smith, the driver of the tractor-trailer truck noticed smoke in his rearview mirror around 2:30 a.m. and pulled over on exit 98, the exit leading to GPC's Newton campus. No other vehicles were involved or damaged.

The truck was delivering 34,350 pounds of rags coated in paint thinners from a Sherman Williams paint plant in Alabama to an incinerator that powered a concrete plant in South Carolina, said Smith.

The NCFD had to let the fire burn out because of the environmental hazard from runoff if they tried to put out the fire with water, said Smith.

The fire burned for nearly eight hours until approximately 10 a.m. when the truck was hauled away. The driver said it was the third time in 12 years that the rags had spontaneously combust, according to Smith.

Though the truck was cleared and the exit opened by 10 a.m., the Newton campus remained closed for the remainder of the day.