Two elderly friends died of carbon monoxide poisoning when a gas fitter allegedly failed to properly fix the central heating boiler at one of their homes, a court heard today.
The bodies of Margaret Eileen Powell, 72, and Thomas Gwyn Morgan, 74, were found slumped on a sofa at Mrs Powell's home in Hendre Close, Brecon, mid Wales, on 16 December, 2006.
Self-employed gas fitter Peter Tongue, 60, of Llanspyddid, near Brecon, denies two counts of manslaughter and seven offences under the Health and Safety at Work Act.
Cardiff Crown Court heard that Tongue had attended Mrs Powell's home on 4 December, 2006, to carry out repairs on her ducted warm air central heating boiler.
Peter Davies, prosecuting, said that when the boiler was examined, part of it was found to be congested with soot.
"As a consequence, it was giving out carbon monoxide and giving it out in lethal quantities," Mr Davies said.
He said the prosecution alleged Tongue was responsible for the deaths "because when he carried out work for Mrs Powell he failed to carry out work on her central heating system properly".
He said: "It is alleged he carried out work on an appliance of a type he didn't understand ... and took no steps to find out what he should do with that type of machine to do it safely and efficiently.
"He ignored clear and obvious signs of trouble."
Mr Davies said: "There was evidence of a build up of soot inside the workings of the heater, therefore the prosecution say it was not a case of a simple oversight.
"It was a case of a man taking on a job he wasn't competent to do with the result he left the appliance working in potentially lethal conditions."
Mr Davies said Tongue managed to get the boiler working and Mrs Powell paid him £60 for the job, but he failed to detect the blockage of soot which caused carbon monoxide to be emitted into the house.
Tongue was Corgi registered and had worked in the gas industry all his working life, Mr Davies said.
He described Mrs Powell as an active woman who still worked part time as a receptionist in an optician's.
Mr Morgan lived with his son in Cwmavon, Port Talbot, but regularly visited Mrs Powell, a widow he had been friends with for six years.
Mr Davies said the pair were last seen by a neighbour at about 3.30pm on 16 December going into Mrs Powell's house.
When they were found the following day, the oven was on and contained the remains of two burnt jacket potatoes. An opened pizza box was on the kitchen work top.
Mr Davies told the jury: "Carbon monoxide is a colourless, odourless, tasteless, poisonous gas, produced by the incomplete burning of carbon based fuels.
"Carbon monoxide can kill quickly without warning."
He said that when tests were carried out on the boiler after it was cleaned of soot, it worked efficiently without producing carbon monoxide.
It was gross negligence on Tongue's part that led to the friends' deaths, he said, as he owed them both a duty of care to carry out work to recognised standards, competence and efficiency and failed to do so.