Authorities say a South Carolina mother who died in a fire with her twin 3-year-old sons had left them alone in her house with food on the stove when the blaze broke out.

Charleston County Sheriff's spokesman Maj. John Clark says 30-year-old Mary P. Brown of Charleston had left the house to pick up a friend Tuesday evening.

Clark says the woman returned to find the house engulfed in flames and then ran inside to rescue the boys. She brought one of the children outside to her friend, then went in for the other. Firefighters found her inside the home, not far from the other boy.

Charleston County Deputy Coroner Kelly Myers says all three died of smoke inhalation.

Assistant Fire Chief Raymond Lloyd says the fire was caused by the food left unattended on the stove.