The mother of one of the two teenagers who died after being poisoned by carbon monoxide has vowed to continue her fight to highlight the dangers of the silent killer.
Catherine McFerran succeeded in bringing about a change in the law that means carbon monoxide alarms must be fitted in any newly-built home in Northern Ireland.
The heartbroken mother said after the death of her son Neil that she didn't want any more families to go through the same suffering her family endured.
Both families have fronted a drive for a change in legislation governing building regulations that cover all appliances that burn fuel.
The law, which came into force in 2012, means alarms must also be used when a new or replacement boiler or heater is installed in an existing house.
The new requirement was ushered in by then Finance Minister Sammy Wilson, who promised to address the issue following the death of the teenagers in 2010.
Speaking after gas fitter George Brown pleaded guilty to the manslaughter of Neil and his friend Aaron Davidson, Mrs McFerran said she would continue to raise awareness of carbon monoxide.
"We don't want anyone else to be in that situation and what we are going through," she previously said. "If there had been an awareness, it could have been a different story for us and for Neil."
She welcomed the development at the time, but said that more still needed to be done.
"I have to say, I think it's a very positive step with Northern Ireland taking the lead on this," she said.
"It's a good first step, but more must be done, as this only covers a small proportion of homes."
When the new legislation was introduced, a UK-wide survey at the time showed that only 39% of homes have a carbon monoxide alarm fitted. Of those without a detector, 42% said it was because they had smoke alarms, highlighting a level of confusion between the two types of alarms.
Since her son's loss, Mrs McFerran has campaigned tirelessly for greater awareness of the dangers, setting up the Gis A Hug Foundation in a bid to prevent future tragedies.