LANCASTER TWP — An elderly driver was killed Sunday night in a rollover wreck on Interstate 79 near Zelienople, authorities said.

The 79-year-old Pittsburgh man was southbound about 8 p.m. when he lost control of his small pickup truck on the highway about two miles past the Portersville exit.

State police are investigating but a report was not available this morning and investigators did not release the man’s name.

Witnesses told authorities the man’s Chevrolet S-10 apparently sideswiped another vehicle before he traveled off the right side of the road, hit an embankment and overturned. The man, who was not wearing a seat belt, was thrown out of the truck, which ended on its wheels.

“It was a fairly violent wreck,” said Chief Neal Nanna of the Harmony Volunteer Company.

Butler County Chief Deputy Coroner John Hanovick pronounced the victim dead of severe injures to the head and chest about 8:50 p.m. The man likely died on impact, Hanovick said.

No autopsy was planned but Hanovick said toxicology tests would be done as part of the investigation. Authorities, however, said they had no reason to suspect alcohol or drugs were factors in the crash.

Harmony and Zelienople volunteer firefighters assisted with traffic control at the scene.

Nanna said the wreck closed one of the southbound lanes on the interstate for about three hours, which caused a traffic backup during the end of the Easter weekend.