(Update 11-2-17) This story has been updated to reflect a preliminary cause of death.

A man and a woman died in two separate events that both involved fires.

One of the fires appears to have been caused when a bedridden woman who was on oxygen smoked a cigarette, said Picayune Fire Marshal Pat Weaver. The department was called to the fire at 14 Wilma Stockstill Road on Oct. 27 at 2:30 p.m.

Firefighters responded to find 70-year-old Wilma Hutchinson Stockstill had died in the fire. Weaver said it appears the fire broke out when Stockstill smoked a cigarette while using oxygen.

“Smoking and oxygen is just not a good combination at all,” Weaver said.

Pearl River County Coroner Derek Turnage said that a preliminary autopsy reveals Stockstill did not suffocate from smoke inhalation because there was no soot in her upper airway, leading investigators to believe she died of natural causes before the fire began. However, the investigation is still underway to determine her cause of death. Turnage said it is believed she was smoking in the home with an oxygen concentrator, which is suspected to be the cause of the  fire.

A second death associated with fire was reported early Thursday when the Pearl River County Sheriff’s Department received a call at 2:35 a.m. from a passerby that a vehicle was on fire in the ditch in the 100 block of Otis Stewart Road, said Chief Deputy Shane Tucker.

Emergency personnel arrived to find the vehicle, a 2004 Mercury Grand Marquis, fully involved, preventing them from determining if anyone was inside. Tucker said it wasn’t until the flames were extinguished that a driver was found inside.

Due to the extent of the burns to the vehicle and deceased, positive identification has not been made. Tucker said the department knows who the car is registered to, but will wait until positive identification is made before releasing additional information.