RALEIGH, N.C. (AP) – A fiery crash involving three large trucks killed two people Friday and closed Interstate 85 in one direction, authorities said.

The accident happened shortly before 10 a.m. on Interstate 85 when a tractor-trailer struck two trucks parked on the shoulder. The driver told troopers that she lost control of her rig, Highway Patrol spokesman Lt. Everett Clendenin said.

Two of the trucks caught fire, but there was no release of hazardous materials, Clendenin said. At least one medical helicopter landed on the interstate to evacuate the injured.

The driver and a passenger in one of the trucks were killed. Two other drivers were injured, Clendenin said. They were treated and released from Duke University Hospital in Durham, a hospital spokeswoman said.

The wreck occurred near Butner, about 20 miles north of Raleigh. Smoldering debris littered the interstate, and southbound traffic backed up for miles.

The lanes were expected to remain closed until late Friday.