The dead woman, named locally as Mary “Mai” O’Regan, had been living in sheltered housing in Skibbereen, Co Cork, with her 88-year-old brother, Jack.
The fire was spotted at about 4.45am yesterday by a man who was out for a walk.
He was unable to get in the front door of the house at No 8 Convent Hill and immediately phoned the fire brigade.
The emergency services arrived shortly afterwards and smashed down the front door.
Ms O’Regan was brought outside where attempts were made to resuscitate her.
However, she was pronounced dead at the scene a short time later by a local doctor.
Her body was taken to the mortuary at Cork University Hospital where a post mortem exam was carried out yesterday by assistant state pathologist Dr Margaret Bolster.
It is believed that a candle caused the fire in Ms O’Regan’s bedroom and that she may havedied from smoke inhalation.
The fire was confined to her room and there was no damage to the rest of the building.
Jack, who was in another room in the house, was rescued by members of the emergency service and taken to Bantry General Hospital. A Health Service Executive (HSE) spokesman said he was in a comfortable condition.
It is expected that Mr O’Regan will shortly be transferred to Skibbereen Community Hospital where he will continue his recuperation.
Superintendent Pat Maher, who is leading the Garda investigation, said that following a thorough forensic examination of the scene he was satisfied the fire was a tragic accident.
He said if it wasn’t for the prompt action of the person who noticed the blaze, there could have been even more serious consequences.
The brother and sister, who were originally from Ballydehob, were living in the bungalow, which is owned by the Skibbereen Geriatric Society.
Skibbereen-based county councillor Brendan Leahy said the brother and sister were very united and very friendly people.
He said Ms O’Regan’s death was very sad and she would be mourned by the whole community.