WOLF CREEK TWP, Mercer County — Authorities are looking for the hit-and-run driver of a tractor-trailer they say struck and killed a retired state police lieutenant who had stopped to fix his car Thursday evening on Interstate 80.

State police are asking anyone who saw the crash or has information about the suspect vehicle or its driver to call the Mercer station at 724-662-6162.

Billy Ray Williams, 64, of Erie was outside his older model Lincoln in the right eastbound lane about 6:15 p.m. when he was struck by the rig, state police said.

Williams, who retired in 2005 after 36 years with the state police, was taken to the Grove City Medical Center where he was pronounced dead about an hour later.

Mercer County Deputy Coroner John Libonati said Williams died of massive head and chest injuries at 7:14 p.m.

Police believe Williams was traveling east when a cord he used as a makeshift hood latch came loose. He stopped to secure the hood.

A witness behind the tractor-trailer told investigators that Williams walked across the front of his car toward the driver's side and stepped into the left lane. The tractor-trailer was changing lanes when it hit Williams.

Superior Ambulance paramedics treated Williams before he was rushed to the hospital.

Williams enlisted with the state police in May 1969.