PITTSBURGH — The driver in the Monday morning crash near the Lawrence-Butler County line that killed his girlfriend died of injuries later that night, authorities said.

Edward Sturges, 59, of Shenango Township was pronounced dead at 8:38 p.m. at UPMC Presbyterian hospital in Pittsburgh.

Sturges died of severe injuries to his head and chest, according to the Allegheny County Medical Examiner’s office.

His passenger and girlfriend, Beverly K. Hassinger, 59, of Shenango Township, was pronounced dead at the scene after the crash shortly before 8 a.m. in Slippery Rock Township, Lawrence County.

State police said Sturges was traveling east on Route 422 near Fox Road when he applied the brakes and lost control of his 2008 Chevrolet Cobalt.

Rescuers said the highway was slushed covered and slippery at the time.

The couple was headed to Cranberry Township where Hassinger had a routine doctor visit scheduled, said Lawrence County Coroner Russell Noga.

Sturges’ car crossed into the westbound lane and was struck on the rear passenger side by a tractor-trailer traveling west. The truck driver, Ovidiu T. Tihauan, 44, of Mundelein, Ill., was not injured.