St. Johns County Sheriff's Office detectives and state Fire Marshal's Office are investigating the discovery of a dead woman inside a burning Porta Potty early Saturday morning in St. Augustine.

St. Johns County firefighters discovered the body of an unidentified woman inside a burning Porta Potty early Saturday at St. Augustine home under construction.

The victim was too badly burned for immediate identification. However, St. Johns County Sheriff's Office detectives believe the victim was a white woman.

Detectives are asking the public for help identifying her and determining the circumstances of her death, said Chuck Mulligan, a Sheriff's Office spokesman.

"At this time, we have not received an missing persons reports that may coincide with this incident," Mulligan said.

"We are asking anyone who may have a family member or friend, who has not been heard from and may be missing, to contact the St. John’s County Sheriff’s Office and ask for the Major Crimes Unit," Mulligan said.

Mulligan also said the case "remains an undetermined death investigation pending autopsy findings and/or additional background information."

Because of the condition of the body, the victim's age and how she died wasn't immediately known, he said.

Mulligan said the body was taken to the Medical Examiner's Office for an autopsy and potential identification. The autopsy is expected to be performed Monday, he said.

St. Johns County Fire Rescue first responders discovered the body about 7:30 a.m. when called to the portable toilet on fire in the 500 block of Horseshoe Road North in the area of Florida 16 and U.S. 1 — not far from St. Augustine High School.

The portable toilet was at a home that has been under construction for several months.

Mulligan said this appears to be the first case of its kind in the county.

There were several possible scenarios for how the death happened. Detectives will explore all possibilities, he said.

"A person could have gone in there and the methane gas could have ignited somehow … it might have been a suicide or something more nefarious. We just don't know at this juncture," Mulligan said.

It also was possible the victim died of a medical issue while smoking and the lit cigarette sparked the fire. Or it might have been drug-related, he noted.

"In my 32 years in law enforcement, I've never seen one of these before," Mulligan said.

Mulligan said Sheriff's Office detectives along with state Fire Marshal's Office investigators and the Medical Examiner's Office are investigating the death.

"The investigation is preliminary at this point. The state Fire Marshal will research the cause of the fire and if any accelerants were used and the like," Mulligan said. " The Medical Examiner will tell us what the cause of death was and if there were any indicators if the body had trauma to it prior to the fire."

Anyone with information can call the Sheriff's Office Major Crimes Unit at (904) 824-8304.

Teresa Stepzinski: (904) 359-4075