Arturo López Hernández was in the Haizea Bar with four colleagues from the Traffic Brigade. He was off duty and dressed in civilian clothes. At around 11:45 pm, three terrorists, armed with machine guns burst into the bar, while another two waited outside. They opened fire, killing four of the five officers and another customer who was in the bar at the time. They then shot them again as they lay on the ground. Another six people were wounded in the brutal attack. Judging by the large number of shell casings found in the bar, around sixty shots are believed to have been fired.
As well as Arturo López, civil guards Julio César Castillejos and Modesto García and lance corporal Ángel Retamar were also killed in the attack. Miguel Lasa, a hairdresser, who was drinking in the bar, was also killed and four other locals from Zarauz were injured: Basilio Elola, Antonio Izquierdo, Ismael Aguirre and Izaskun Garmendia.
On the following day, the town council of Zarauz unanimously condemned the attack, with the support of all the councillors, including those from Herri Batasuna.