Crews clear a head-on collision Tuesday on Route 8 in Penn Township south of Butler. Seb Foltz/Butler Eagle

PENN TWP — A medical emergency may have caused a driver traveling north on Route 8 to cross into the southbound lanes and strike a couple, whose SUV rolled on to its passenger side Tuesday morning, police said.

Township firefighters pried open the driver’s side doors and cut through the roof to free the couple, who are in their late 60s. Police said the wife was flown to Allegheny General Hospital in Pittsburgh and her husband was taken there by ambulance.

The northbound driver, who was also driving an SUV, is a diabetic and likely suffered a medical emergency at the wheel, police said. He was evaluated at the scene by paramedics, but refused treatment, police said.

The crash occurred just before 9 a.m. a short distance south of Thorncrest Drive.

Middlesex Township police and the township volunteer fire department along with state police and Butler Ambulance Service responded to the accident. The injured woman was taken to the Pittsburgh-Butler Regional Airport and transferred to a medical helicopter for the flight to AGH.

Both southbound lanes were closed and southbound traffic was diverted to the center turning lane until the vehicles were removed at approximately 10:50 a.m.