Gardaí have made a sixth arrest in the murder probe into a Waterford arson attack that killed four family members. A man in his 20s was arrested this afternoon and is being questioned at a Garda station in the southeast, with the National Bureau of Criminal Investigation assisting local officers. The arrest comes as Gardaí say further searches will be carried out. The victims, Philip English and partner Kim, along with their sons Callum, 12, and Jayden, 9, died after a fatal house fire in the Birchwood area of Waterford City shortly after 5am on Tuesday, October 13, 2026. Two other young children were rescued from the home by emergency services but suffered serious injuries. Two people have been charged in connection with the investigation. Four more people are currently in Garda custody, and the periods of detention for two individuals arrested on Monday, October 20, have been extended for further questioning. Gardaí said the man arrested this afternoon was detained under Section 72 of the Criminal Justice Act 2006 as amended by Section 6 of the Criminal Justice (Amendment) Act 2009. Gardaí continue to appeal for anyone with information to contact Waterford Garda Station or the Confidential Line at 1800 666 111. The investigation is ongoing, with officers continuing searches and questioning suspects as the probe into the multiple murder continues.