An elderly couple died in a house fire caused by a gas leak from a portable gas heater at their home in Nelson, Caerphilly borough, an inquest has heard. William Mumford, 90, and Marlene Mumford, 84, were found dead inside the property at Heol Fawr when emergency services gained access.
Gas cylinder carried into home
The inquest at Gwent Coroners' Court heard that on December 12 last year, at around 10.15am, resident Alvin Adams was walking to the pub when he saw the couple outside their home. He noticed Mr Mumford struggling to carry a 13kg propane gas cylinder from the car into the house.
Mr Adams said: "I said something along the lines of: 'Do you need a hand?' To which he replied: 'Yes, thank you.' So I carried the gas cylinder into their porch." He added that he noticed dirt and rust on the bottom of the cylinder but was not concerned by what he saw.
Flames spotted from pub
Hours later, Marcus Rhys Paul was in the smoking area of the neighbouring Tyler's Arms pub, opposite the house. At around 5pm he saw flames coming from the front of the property, describing them as six feet tall and visible from "over the wall".
Mr Paul ran around the house and tried to get inside, then returned to the pub for help and to call emergency services. He noticed a gas cylinder outside the property on its side, which exploded as he was seeking help inside the pub.
Emergency response and investigation
When emergency services arrived 15-20 minutes later, they could not access the property due to the extent of the damage. Looking through the doorway, paramedics from the Welsh Ambulance Service saw the bodies of both Mr and Mrs Mumford, who were visibly deceased.
Post-mortem evidence showed both had inhaled significant amounts of carbon monoxide. Mrs Mumford had a carboxyhaemoglobin level of 43.9% and Mr Mumford 27.8%, findings indicative of carbon monoxide poisoning.
Gwent Police DCI Neil Blyth told the inquest investigators initially considered three possibilities: accidental fire, negligence, or third-party involvement, including a possible problem with the gas cylinder and deliberate ignition. However, house-to-house and CCTV enquiries found no evidence of third-party involvement. A gas cylinder recovered from outside was undamaged, though its regulator was missing and parts of the heater, including the hose, had been destroyed.
Cause of fire determined
A South Wales Fire and Rescue Service investigation found the fire began in a television room adjoining the living room, where a portable gas heater had been positioned in the doorway. Station commander Melvin Robert Laidler told the coroner the fire was caused by an uncontrolled release of gas from the heater, linked to a missing or damaged jubilee clip or another mechanical or connection failure. The resulting ignition spread the fire rapidly through the house.
The fire service had attended the property in 2017 after a smaller fire caused by unattended cooking. Smoke alarms and other fire safety measures were installed then, but investigators could not establish whether they were still operational.
The inquest heard Mrs Mumford had worked in a factory and Mr Mumford was a coal miner. They regularly used the portable gas heater, sometimes connected by their son Karl Mumford and sometimes by William himself.
Pathologist Dr Richard Jones gave the medical causes of death as 1a: exposure to the combustion products of a fire. Assistant coroner Sarah Le Fevre accepted this and concluded both deaths were accidental.
Ms Le Fevre said: "The fire originated in the back room of the property, likely in process of fitting a new cylinder to the heater. A spark would have been enough to start the blaze and it spread quickly due to items surrounding the fire such as a sofa."
She added: "William realised the fire had taken and he was unable to control it and therefore thought the best cause would be to try and remove the fire from the house. He took the fire from the back room, through the living room and into the porch. He tried to take the cylinder outside in an effort to minimise its spread."
Ms Le Fevre described the incident as a "terrible, desperately sad, singular event".
