The Warrenpoint ambush or the Warrenpoint massacre was a guerrilla assault by the Provisional Irish Republican Army (IRA) on 27 August 1979. The IRA attacked a British Army convoy with two large bombs at Narrow Water Castle (near Warrenpoint County Down. It resulted in the British Army's greatest loss of life in a single incident during "the Troubles", with 18 soldiers being killed.

Ambush:

First explosion:

At 16:40, a British Army convoy consisting of one Land Rover and two four-ton trucks was driving past Narrow Water Castle on the A2 road. As it passed, a 500 pounds (227 kg) fertiliser bomb-hidden in a lorry loaded with strawbales and parked close to the castle-was detonated by remote control. The explosion caught the rear truck in the convoy, killing six members of 2nd Battalion, The Parachute Regiment.

After the first explosion the British soldiers, believing that they had come under attack from the IRA, began firing across the narrow maritime border with the Republic of Ireland, a distance of only 57 m (187 feet). An uninvolved civilian, Michael Hudson-an Englishman whose father was, by coincidence, a coachman at Buckingham Palace-was killed by British forces during the shooting, and his cousin Barry Hudson wounded. According to RUC researchers, the soldiers may have mistaken the sound of ammunition cooking off from the destroyed Land Rover for enemy gunfire from across the border. However the hands of two IRA members arrested by the Gardaí and suspected of being behind the attack, Brendan Burns and Joe Brennan, showed traces of firearms. Author Peter Taylor asserts that there was sniper fire on the soldiers after the first bomb ripped through the truck.

On hearing the first explosion a Royal Marine unit alerted the British Army of an explosion on the road and reinforcements from the Parachute Regiment were dispatched to the scene by road. A rapid reaction unit consisting of medical staff and senior commander Lieutenant-Colonel David Blair-the commanding officer of the Queen's Own Highlanders-together with his signaller Lance Corporal Victor MacLeod, were sent by Wessex helicopter. Col. Blair assumed command once at the site.
Second explosion:

At 17:12, thirty-two minutes after the first explosion, a second device concealed in milk pails exploded against the gate lodge on the opposite side of the road, completely destroying it. The IRA had been studying how the British Army acted after a bombing and correctly assessed that the soldiers would set up an Incident Command Point (ICP) in the nearby gate house.

The second explosion, caused by an 800 pounds (363 kg) fertiliser bomb, killed twelve soldiers-ten from the Parachute Regiment and the two from the Queen's Own Highlanders. Mike Jackson, then a Major in the Parachute Regiment, was at the scene soon after the second explosion and later described seeing pieces of human remains over the area and the face of his friend, Major Peter Fursman, still recognisable after it had been completely ripped away from his head by the explosion. Only one of Colonel Blair's epaulettes remained to identify him as his body had been vapourised in the blast

Aftermath:

Two men arrested after the bombing, Brendan Burns and Joe Brennan, were later released on bail due to lack of evidence.

Warrenpoint happened on the same day as Lord Louis Mountbatten, a cousin once removed of HM Queen Elizabeth II, was killed by an IRA unit near Sligo along with several others. The death of such a senior royal made the Warrenpoint ambush a footnote in that day's British news although, ultimately, the death of 18 British soldiers increased the move to Ulsterisation.

According to Toby Harnden, the attack "drove a wedge" between the Army and the RUC. Lieutenant General Sir Timothy Creasey, General Officer Commanding Northern Ireland, suggested to Margaret Thatcher that internment should be restored and that liaison with the Gardaí should be left in the hands of the military. Sir Kenneth Newman, the RUC Chief Constable, claimed instead that the British Army practice, already in place since 1975, of supplying their garrisons in South Armagh by helicopter gave too much freedom of movement to the IRA.

Lt. Col. Blair is remembered on a memorial at Radley School.