At 16:40 a 500 pounds (227 kg)
fertiliser bomb hidden in a lorry loaded with
strawbales, parked close to
Narrow Water Castle, was detonated by
remote control as an army convoy of a
Land-Rover and two four-ton trucks drove past on the
A2 road. The explosion caught the rear truck in the convoy killing six members of
2nd Battalion, The Parachute Regiment.
[13]
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).
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 home-made bomb, killed twelve soldiers - ten from the Parachute Regiment died along with the two Queen's Own Highlanders soldiers.