A gas-fitter has been sentenced to two years in prison and two on licence for the manslaughter of two teenagers in 2010.
George Brown, 52, from Ballygawley Road, Aghadowey, admitting killing Neil McFerran and Aaron Davidson and a string of other charges, including health and safety breaches.
The pair died after they were overcome by carbon monoxide from a faulty boiler in Castlerock. Brown was also fined £19,000.
The 18-year-old friends, from Newtownabbey, died in a holiday home apartment on 3 August, 2010.
A third teenager was also overcome by the gas, but despite suffering serious injury, he survived.
An investigation found that the gas leak had been caused by a defective flue in a boiler.
The judge described what happened in the Castlerock apartment as a “wholly avoidable tragedy”.
He told Brown that his “cavalier attitude” to the dangers of carbon monoxide was reprehensible and impossible to comprehend.
The investigation found there had been a failure to properly secure a join in the flue system, which allowed carbon monoxide to leak into the apartment.
A section of the flue was completely separated, while the collar between two sections of the flue was not secured with screws to hold the joint in position.
The judge said the failure of the gas-fitter or his employees to secure the boiler’s flue pipe with four screws was “sheer laziness”.
Brown, a father-of-two, had admitted causing the manslaughter of Mr McFerran and Mr Davidson on the grounds of gross negligence.
While he made the case that he did not personally install the boiler and flue, he accepted the supply and installation of the heating system was his responsibility.
He also admitted 19 other charges including health and safety breaches relating to work undertaken at the apartment in Castlerock, as well as defective workmanship carried out by both him and his employees in and around the greater Coleraine area.
For each of the 19 charges he was fined £1,000, and was given a year to pay the entire £19,000 penalty.
The judge said that following the publicity surrounding the teenagers’ deaths several people in the Coleraine, Portrush and Portstewart areas who had work undertaken by Brown’s business came forward.
Various safety breaches were discovered when these installations were examined.
The judge told the court that this highlighted a “litany of shoddy workmanship”.
He said the publicity and subsequent investigations in other properties “may have saved other customers from death or serious injury.”
The teenagers’ parents were in court to witness Brown being jailed.
The judge spoke of the impact the deaths have had on the families concerned, telling the court: “They have been gravely and permanently affected by the loss and the near loss of their boys.”
The gas-fitter sat with his head down as the sentence was delivered.