ERIE — A Butler County woman found lying in a downtown alleyway died from hypothermia and alcohol toxicity, investigators said.

Abrielle Marie Brynda, 21, of Zelienople was discovered unresponsive Feb. 1 between two buildings, one had an apartment where she had attended a party the previous night.

Erie County Coroner Lyell Cook said Wednesday that Brynda’s death was accidental.

“She died of complications of hypothermia in the setting of acute alcohol intoxication,” he said.

Investigators this week released findings from autopsy and toxicology reports in the death of Brynda, a 2011 Seneca Valley graduate and junior nursing student at Gannon University in Erie.

She had a core body temperature of 70 degrees when rescuers reached her, Cook said. Hypothermia, he noted, sets in once the body’s temperature drops below 95 degrees.

She also was legally intoxicated with a high blood-alcohol level, authorities said.

Cook would not release the specific blood-alcohol level but characterized it as “well over the (legal) limit.” But, he added, “less than three times (the limit).”

In Pennsylvania, a blood-alcohol content of 0.08 percent is considered the legal limit for driving.

Additionally, Cook said Brynda had “medication” in her system but “none of any significance.”

He would not identify the drugs, but none were narcotics.

Brynda’s family members found her just before 4 p.m. Feb. 1 below a window of a second-floor apartment at 144 W. 12th St., where a party had been held the night of Jan. 31.

The family went looking for her when she failed to return home following the party. Erie Police later joined in the search.

She had a faint pulse when paramedics arrived.

Erie Police Chief Randy Bowers said he suspects Brynda possibly stumbled or fell after leaving the apartment, and hit her head on the pavement.

An autopsy the following day ruled out foul play.

Investigators did not know for certain why Brynda stepped out of the apartment, leaving her coat and purse behind.

For nearly 13 hours, she apparently remained helpless and hidden in the alley, or walkway, between the buildings.

The pre-dawn temperatures Feb. 1 were in the low 20s.

“She had significant hypothermia,” Cook said, “but she was still alive.”

Brynda was taken to the trauma center at UPMC Hamot in Erie, where doctors began special techniques to warm her body. But about 90 minutes later, Cook said, she was pronounced dead.