LANCASTER TWP — The Butler County Coroner's Office says its investigation into the death of a Pittsburgh man who was hit and killed while walking across Interstate 79 Wednesday is ongoing.

An autopsy of 41-year-old Beau Marquis determined that Marquis died as a result of blunt-force trauma, said Deputy Coroner John Hanovick.

Hanovick said the office is still working to determine the manner of Marquis' death — an important ruling when investigators are deciding whether to file criminal charges in a death.

“It's a tough call,” Hanovick said. “We don't know what's going on.”

Hanovick also said that officials had also been unable, as of Friday morning, to contact Marquis' family and notify them of his death. Officials were still reaching out in hopes of contacting the family through Marquis' employer, Hanovick said.

State police have said that Marquis was crossing the southbound lanes of I-79 at about 9:30 p.m. Wednesday when he was struck by a tractor-trailer.

Marquis was taken to UPMC Passavant hospital in Cranberry with what Harmony Fire District Chief Scott Garing called “severe traumatic injuries.”

Marquis was pronounced dead at the hospital that night.