A couple and their two sons were killed when their home in Waterford was set alight in an arson attack over a suspected €20,000 drug debt. Kim English, 30s, her husband Philip, 50s, and their sons Callum, 12, and Jayden, nine, died after the property was targeted early on Tuesday in the Birchwood estate, about 3km from Waterford city centre. Philip’s son John James English told RTÉ the family had been terrorised for years by gangland figures in Waterford over a drug debt owed by someone else. He said the home of Philip’s ex-wife, Anne, was previously hit by a petrol bomb. Police investigating the quadruple deaths believe three brothers linked to an organised crime gang ordered the attack. Gardaí are treating the victims as “totally innocent people”, with sources saying tensions are high and there is fear of further violence. The investigation has triggered multiple raids across Waterford. Officers seized cars as well as phones and other electronic devices, which are being examined. Gardaí have said there are people who know who carried out the attack and urged them to come forward. The investigation is ongoing and no arrests have been made so far. Meanwhile, Philip’s family gathered at the scene and released balloons in honour of the victims. Hundreds turned out for a vigil at Sacred Heart Church. Another child, Nadia, 14, and her brother Elliot, six, are still in critical condition in hospital after the fire. Gardaí said the investigation remains active, with further technical examination under way.