Three people were seriously injured Monday afternoon when a woman fell asleep at the wheel and slammed into a car parked on the shoulder of I-85, authorities said.

The wreck occurred in the northbound lanes of the interstate near mile marker 40 in Coweta County, according to sheriff’s office spokesman Maj. Mark Fenninger.

All three people inside the car suffered serious injuries, and a passenger in the back seat was taken by helicopter to Atlanta Medical Center. There was no one in the second car, which had been left on the emergency shoulder.

According to investigators, the woman driving nodded off and left the road before slamming into the parked vehicle. Inside her car, deputies discovered several bags of methamphetamine as well as syringes, authorities said.

The crash is still being investigated, and police have not released the names or conditions of anyone injured. It’s also unclear what charges the driver may face.