On 27 August 1979, Lord Louis Mountbatten, 79, was killed when a bomb planted by the Provisional IRA detonated aboard his fishing boat, Shadow V, in the waters off Mullaghmore, County Sligo, Ireland. The bomb, concealed on the vessel the night before, was remotely detonated as Mountbatten and family members set out from the harbour. Three others died in the blast, including his 14-year-old grandson Nicholas Knatchbull and a 15-year-old local boy.
Thomas McMahon, an IRA bomb-maker, was arrested hours before the explosion on unrelated grounds and later convicted of the murders based on forensic evidence linking him to the boat. The attack was coordinated with the Warrenpoint ambush the same day, which killed 18 British soldiers, making 27 August 1979 one of the deadliest days for British forces during the Troubles.
