The charred remains of an unidentified woman were discovered Saturday morning inside a Florida portable toilet, police said.

St. Johns County Fire and Rescue responded to a port-a-potty on fire at around 7:30 a.m. Saturday morning in St. Augustine, Florida, a coastal town 50 miles south of Jacksonville. After extinguishing the flames, the firefighters found human remains inside the portable toilet, the county sheriff’s office said in a statement.

Detectives believe the remains belong to a white woman and don't have more information at this time.

The incident occurred on the property of a home construction site, where neighbors say they heard a loud boom at 6:30 a.m. Saturday, according to NBC affiliate First Coast News.

"I heard there were flames 15 feet in the air," Jan Long, whose property is next to the site of the fire, told First Coast. "Our land that borders that land is all burnt now."

Investigators, including state fire marshals, are currently working to understand the source of the flames. The woman might have lit a cigarette inside the port-a-potty, sparking the blaze, the sheriff’s office said.

The case has not yet been classified, and authorities will announce the official cause of death when they receive the autopsy report. Police are asking that anyone with more information about the fire or the woman’s identity come forward.