An elderly Ossining woman was likely killed instantly Thursday when another driver hit her head-on.

Police say a 55-year-old driver crossed the yellow lines on Route 9 into the southbound lanes, striking a car with two 80-year-old women inside it. The 80-year-old driver died and her passenger was taken by helicopter to Westchester Medical Center for treatment.

The 55-year-old woman, a Putnam County resident, suffered non-life threatening injuries and was also taken to the hospital.

Several miles of Route 9 were shut down for nearly four hours of rush-hour traffic.

At this point, police do not believe speed contributed to the crash. It is not clear whether drugs or alcohol may have played a role in the accident yet either.