SOUTH BUFFALO TWP, Armstrong County — Donald M. Mastandrea's death has been ruled an accident.

More like a freak accident, according to investigators.

The body of the 33-year-old Shaler Township man — the father of two young children — was found just 200 yards from his camp site Tuesday.

Mastandrea had been missing for nearly a week when searchers discovered his body about 11:30 a.m., one mile north of the Allegheny River along Dock Hollow Creek in South Buffalo Township.

An autopsy Wednesday listed the cause of death as “exposure to the elements, due to thermal injuries of head, back and torso,” said Brian Myers, Armstrong County coroner.

But how he apparently met his fate struck even Myers as strange.

“We believe he fell into his own campfire,” the coroner said, “and caught his shirt on fire. He then took off running.”

Mastandrea eventually collapsed where searchers found his body. Several shirts he had been wearing had been burned.

The autopsy revealed he had first- and second-degree burns to his back, chest and neck area.

But while the burns were factors in the death, authorities said, they were not the primary cause.

“Hypothermia,” Myers said, is what killed Mastandrea.

Investigators, meanwhile, are still waiting for toxicology reports that are likely weeks away. Those results could confirm suspicions that Mastandrea had been drinking at the campsite.

Myers said authorities found at least one bottle of vodka there.

Alcohol consumption may explain why Mastandrea ended up falling into the fire.

But one question that will likely never be answered is when he died.

Mastandrea's family on Monday reported him missing to local police, authorities said. The last contact he had with family was five days earlier at about 6:30 p.m. Jan. 25.

Local police, firefighters and members of Mastandrea's family formed a search party and took off looking for him Tuesday morning.

From the autopsy findings and general observations, Myers said, it was likely that Mastandrea was dead “at least a few days” before his body was recovered.

Inside his pants pocket, investigators found Mastandrea's cell phone.

At his campsite, they found a tent, tarp and a makeshift clothes line. Authorities said he was familiar with the area and had set up camp there before.

Myers said Mastandrea was divorced and had two boys, ages 8 and 10.

The Bock Funeral Home in Shaler Township is handling funeral arrangements.