SLIPPERY ROCK — Investigators have ruled that a 28-year-old Harrisville man died accidentally Wednesday following a night of heavy drinking mixed with drugs.

But Aaron L. Cook did not die of hypothermia, state police said.

Cook’s body was found laying in snow in a wooded area near Copper and Elm streets about 8:20 p.m. Wednesday, more than 18 hours after he was last seen leaving a Slippery Rock bar.

He was found just a short walk from the Ginger Hill tavern on South Main Street, where he had been drinking with friends since Tuesday night, police said.

An autopsy Thursday night determined that Cook did not die from an assault, according to police Cpl. Daniel Herr.

“This absolutely was an accidental death,” Herr said.

But a cause of death is still pending toxicology reports and tissue analysis. Those findings, however, are expected to take at least several weeks.

Investigators said Cook left the bar between 1:30 and 2 a.m. Wednesday, just after “last call” sounded. He walked out without taking his coat.

Surveillance video shows him at the tavern and leaving.

Possibly from having consumed a large amount of alcohol, coupled with using drugs during that time, Cook may have become disoriented after walking away from the bar, Herr said.

Police would not identify what kind of drugs they think Cook was using that night.

Herr said investigators theorize that Cook at some point fell down and got up. He walked another 20 or 30 yards before falling down again. After the second fall, he never got up.

There was only a small trace of blood on his face, which possibly was due to one of the falls, or both, investigators said. He still had his wallet with him.

When Cook did not return home, his wife at some point called friends and acquaintances to help search for him.

Cook did not have a car with him, having earlier gotten a ride to Slippery Rock, which is about 7 miles from his home.

His body had been outside in the bitter cold for about 18 hours when it was found, and authorities initially wondered if Cook had frozen to death.

But the autopsy ruled out hypothermia as a cause of death, Herr said. Those findings indicated he died before the elements took effect.

Alcohol and drug toxicity, Herr acknowledged, is another cause of death that police have not ruled out.