FRANKLIN PARK, Allegheny County — State police were trying to figure out why a woman was walking in a vehicle lane before she was struck and killed this morning by a motorist on Interstate 279.

The incident happened in the northbound lanes of I-279 about 4 a.m. today, in the suburb of Franklin Park. That’s about 10 miles north of Pittsburgh.

The Allegheny County Medical Examiner’s office has confirmed the woman’s death, but did not immediately release her identity.

State police say the driver of the minivan that struck the woman stopped at the scene. The accident happened north of the Camp Horne Road exit, but before Interstate 279 merges with Interstate 79.

Police were trying to determine why the woman was walking on the highway.