JEFFERSON TWP — State police received a call about an erratic driver moments before a fatal head-on crash Monday evening on Bonniebrook Road.

Karen L. Risinger, 29, of Emlenton, who was not wearing a seat belt, died at the wreck site about one mile north of Route 356 about 6:45 p.m.

Investigators said Risinger was driving north on Bonniebrook Road when her PT Cruiser crossed into the opposing lane and collided with a large truck, owned by a tree service.

“She was driving a PT Cruiser, but you couldn’t make out what it was,” Butler County Deputy Coroner Larry Barr said of the wreck’s aftermath.

Justin R. Lesseski, 25, of Mars, who was driving the International 4700 truck, was not injured. He was wearing a seat belt.

Trooper Chad Savannah said it was not immediately known why Risinger crossed the center line, but investigators did not suspect alcohol or drugs were involved.

Speed, he admitted, may have been a factor.

Authorities said Risinger was apparently headed home from her job as a home health care worker. Just before the crash, she reportedly began tailgating another motorist traveling north on Bonniebrook Road.

The other driver pulled over and called 911.

“The caller said (Risinger) came up on her was close to (the caller’s) bumper,” Savannah said.

Shortly after that call, the PT Cruiser and southbound truck collided.

The truck, owned by BeaverJack Tree Service of Tarentum, Allegheny County, had severe front end damage.