SLIPPERY ROCK TWP - Authorities are investigating if a 41-year-old township woman who died Sunday afternoon suffered a medical emergency before her minivan slammed into a tree in Slippery Rock Township.

Nicole A. McPherson was pronounced dead at Grove City Medical Center following the accident shortly after 3 p.m. in the 200 block of Branchton Road.

State police said McPherson was traveling east when she lost control of her 2006 Chrysler Pacifica and crossed over the westbound lane on Branchton Road. The van traveled into a home's front yard and hit the tree head on.

The van ended up between two trees. The homeowner and other motorists who came upon the crash reported that the woman was unresponsive.

The Slippery Rick Volunteer Fire Company and its ambulance crew assisted police.

Investigators said they do not know if McPherson might have had a medical issue that caused the accident, or if she possibly died of the emergency and not the injuries.

There were no apparent skid marks to indicate that she tried to brake before the van left the road. She was wearing a seat belt.

It was not known if an autopsy was planned. Butler County Coroner William Young III could not be reached for comment this morning.

McPherson worked SGA Bookstore on the Slippery Rock University campus.