Around 100 to 150 other inmates and staffers were injured at the Escambia County Jail's booking area following the blast. Officials said around 600 prisoners were in the building at the time.
Investigators are still trying to figure out what caused the explosion. Kathleen Castro, a spokeswoman for the county, said it was unclear whether the incident had been caused by the severe weather that flooded the county Wednesday morning.
"The building did receive extensive flooding as a result of the rains," she told WALA. "I don't know if that's directly related to the incident that happened this evening or not, we'll be doing an investigation to determine that."
Uninjured inmates were transferred to other facilities as officials continue their search and rescue efforts in the building. Two sweeps had been completed by early Thursday morning.
Inmate relatives have gathered at the scene to monitor the situation.
"We don’t know if they dead or alive," Eva Stewart told WALA. "It’s really frustrating. I can’t sleep not knowing if my child’s okay. I got other family members in there too, I don’t know if they’re okay.”
Officials said Baptist Hospital had treated around 50 victims of the explosion, 12 of whom have been already released. Gulf Breeze Hospital, on the other hand, has received 31 patients and released 3. All victims were treated for minor injuries.