CLAY TWP — Three women were injured Wednesday afternoon in a one-vehicle rollover crash that closed part of Route 8 for about four hours, authorities said.

Two of the injured, believed to be sisters, were flown by medical helicopters to Pittsburgh hospitals following the wreck shortly after 3 p.m. on Route 8 just south of the Switchback Raceway in Clay Township.

State police are investigating but an accident report was not available this morning. Telephone calls to the barracks were not returned.

Authorities said the women’s car was traveling south on the highway when the driver apparently dropped her cell phone. When she reached to pick it up, she lost control of the vehicle.

The car veered off the west berm and spun around before traveling across the other side of the road, hitting a traffic sign, rolling down an embankment and into a field. The vehicle landed on its wheels.

West Sunbury and Unionville volunteer firefighters rescued the driver and two passengers.

The driver, said Chief Greg Brewster of the Unionville Volunteer Fire Department, was taken to the Unionville fire hall, where one helicopter flew her to an unknown hospital.

An ambulance took the front seat passenger to Butler Memorial Hospital, where she was flown to an unknown hospital.

The back seat passenger was treated at BMH.

An accident reconstruction investigation shut down the busy road to traffic until about 7 p.m.