At around 8.00 am on 26 July, 1986, ETA killed Civil Guard Lieutenant Ignacio Mateu Istúriz and officer Adrián González Revilla in the town of Arechavaleta in Gipuzkoa. The terrorists planted a bomb in a grassy field next to the Civil Guard Barracks in the town in the early hours of the morning. The two civil guards were notified of the action and went to inspect the area and to locate and defuse the device. However, the bomb went off and the two were killed.
Adrián González was 29 years old and Ignacio Mateu 27 when they were killed. The two were unmarried and had their whole lives ahead of them.