He was not sure who removed the batteries.
"It was her home and like many people of that generation she enjoyed smoking inside. I hope the message gets across to everybody to make sure their smoke alarms are working," he said.
He wondered, however, if a working device would have saved his mother.
Mr Fraser lives on the same property but would not have heard the alarm.
"And if her dog hadn't woken her in time to get out, I doubt that a smoke alarm would have," he said.
Mr Fraser said his mum was at an age where she had few pleasures other than a smoke and an evening drink and it was impossible to get her to stop smoking.
"There are not many pleasures left in life when you get to that age, but if you do want to smoke inside, make sure your smoke alarms are working." Coroner Brandt Shortland, in a finding released yesterday, said Mrs Fraser died from the direct effects of carbon monoxide poisoning when her Millington Rd home caught fire in the early hours of August 4, 2011. Mr Shortland said the most likely scenario was that Mrs Fraser, who was described as a heavy smoker who liked a drink in the evening, dropped a cigarette down the arm of her recliner chair late on August 3 and it smouldered overnight, setting fire to the chair and a couch.
Mrs Fraser's body was found at 7am on August 4 after Kevin Fraser noticed the windows of her unit blackened. He went inside to find her loyal fox-terrier-cross dog dead outside her bedroom door and his mother dead inside. Mr Shortland said the tragedy was a reminder of the dangers of smoking in the home, particularly when a person has consumed alcohol, and the importance of extinguishing cigarettes properly.
"The investigation confirmed that Mrs Fraser was a chain smoker and would often drop semi-extinguished cigarette butts on the floor when she missed her ashtray ... it was not uncommon for her caregiver to remove tissues filled with cigarette butts that had been stashed either in the couch or near her bed," he said.
A test showed that Mrs Fraser had a blood alcohol level of 142 milligrams of alcohol per 100 millilitres of blood, above the legal driving limit of 80mg. The flat had smoke alarms, but they had been disabled, after constant activation of the alarms through Mrs Fraser's non-stop smoking, he said.
Mr Shortland said the most likely scenario was that Mrs Fraser's dog had discovered the fire and barked outside her bedroom door to raise the alarm.
It is believed she rose from the bed and tried to reach for her walking frame, but probably encountered ingestion of soot and smoke. Mrs Fraser and her dog are then likely to have succumbed to the smoke.
