OAKLAND, Calif. -- Oakland police have a mystery on their hands after the discovery of a woman who was naked and unconscious beneath a freeway overpass near Fruitvale Avenue Monday night.

The woman was found at around 5 p.m. early Monday evening along East 8th Street at Fruitvale after police received a phone call from a passerby. She died at the hospital a short time later.

Officers say the woman still had a faint pulse when they arrived at the scene.

"We found a woman that was unconscious and was transported to the hospital," said Captain Rick Orozco. "She passed away at the hospital. Now we're investigating this and seeing what exactly happened."

Police tell us for now they are treating this as a suspicious circumstances case. Investigators and crime scene technicians searched the area for clues.

It appears that there was some sort of encampment where the woman was found. Authorities tell us they're still trying to determine if foul play was involved.

13-year-old Robert McCorvey, who lives in the area, says he saw paramedics trying to revive the woman.

"I seen them pressing on her stomach to see if she was alive still," said McCorvey.

He says she appears to be the same person he saw fully clothed, huddled in a red blanket underneath the freeway last Friday. McCorvey says she had shoulder-length dark hair, fair skin, probably white or Latino, and appeared to be in her 30s.

When asked if he had seen her the neighborhood before, McCorvey said that he’d only seen her the prior Friday and that "she looked okay."

Neighbors say the area beneath the freeway had been a dumping ground for garbage until the city cleaned it up shortly before Thanksgiving. They say there is some drug dealing and prostitution in the neighborhood, but that Monday evening's discovery is disturbing.

"You don't find things like this happen over here," says area resident Linda Jemison.

"We're done some canvassing [and] talked to a few people in the neighborhood to figure out exactly what occurred," said Captain Orozco.

Oakland police investigators said they hope to solve the mystery of the woman's death with the help of an autopsy.

The coroner's office tells KTVU that autopsy will likely be performed Tuesday.