A Mercer County man who was helping to extract a car from a ditch was killed yesterday when he was pinned between the vehicle and another automobile.

State police said Jason R. Spencer, 29, of Hadley, was a passenger in the Pontiac Transport that slid off Highway 773 in Perry Township and became stuck in the ditch about 4:33 p.m.

A motorist in a Jeep Wrangler stopped to help, positioning his vehicle behind the Pontiac.

Mr. Spencer was hooking up a tow strap to the Pontiac when a third vehicle operated by Walter O. Nelson, 35, of Meadville hit the back of the Jeep, crushing Mr. Spencer between the Jeep and the Transport, according to state police. He suffered a broken neck and was pronounced dead at the scene.