Authorities have released the name of the woman killed in a house fire on Sunday in Sheffield. Delores Ann Birdsell, 74, who lived in the one-story house at 22 Southview Circle, died of smoke inhalation, according to Sheffield Fire Chief Dan Fields. The cause of the fire remains under investigation, but a cigarette that was not put out is “at the top of the list” of possible causes, Fields said. Firefighters were called about 10 p.m. Sunday. The west side of the home was filled with flames when they arrived. The body was found once the fire was under control, according to a statement released Monday. Birdsell’s name was withheld in the days immediately after the fire so family members could be notified of her death. The fire, which caused extensive damage to the home, appears to have started in a sun room or screened-in room at the west side of the house, according to Fields.