An inquest into the deaths of a father and his two children who died just before Christmas 2011 has returned a verdict of accidental death due to carbon monoxide poisoning.
The inquest also heard a recommendation that all homes using combustible fuel have carbon monoxide detectors installed.
Trevor Wallwork, 52, his daughter Kimberley, 12, and nine-year-old son Harry were found dead in the sitting room of their home at Moygara near Gurteen in Co Sligo on 18 December, 2011.
They were found by Mr Wallwork's stepdaughter Vicky Barnes, who had become concerned because she could not contact them.
The Christmas tree lights and television were on in the room where Mr Wallwork was found sitting in an armchair and the two children were lying on the floor.
Coroner Dr Des Moran today described the circumstances as tragic and freak.
A plastic multi-pack bag had apparently been put on the fire as it was smouldering and had gone up the chimney and blocked it.
Sligo's Chief Fire Officer Paul Coyle said that the fire was probably in the later stages of combustion at the time and was not hot enough to melt the bag.
Instead, the fire expanded the bag like a hot air balloon and it obstructed the flue.
With no escape for the gases from the fire up the chimney, they were released into the sitting room.
Mr Coyle said that there is no way the human body can detect carbon monoxide and the family would have died within minutes.
He said it is essential that all homes using any kind of combustible fuel has carbon monoxide detectors installed to prevent such a tragedy recurring.
Mr Wallwork's wife Susan was in Sligo General Hospital being treated for cancer at the time of the tragedy and she died the following June.
Her daughter Vicky attended the inquest today and supported the Chief Fire Officer's call for detectors.
Post-mortems on all three bodies showed exceptionally high levels of carbon monoxide in the blood.
Verdicts of accidental death due to carbon monoxide poisoning were returned with a recommendation from the inquest jury that people fit carbon monoxide detectors in their homes.