On the evening of 9 July 1976 (“the Day of the Sardine”), a large group of local people from Santurce (Vizcaya) set out on a demonstration in favour of an amnesty from the church of Virgen del Mar. Around nine o’clock, the Guardia Civil intervened, arriving with a number of jeeps and plain-clothes officers to break up the crowd and make arrests. On finding themselves surrounded, three of the officers, who were dressed in the traditional costume of arrantzales (Basque fisherman), began firing on the crowd. María Norma Menchaca Gonzalo was hit by the gunfire. She was taken to the San Juan de Dios clinic but was dead on arrival. Two other people were wounded. According to local people, those responsible were known in the town to be members of the Warriors of Christ the King (Guerrilleros de Cristo Rey).
María Norma Menchaca, a native of Santurce, had two sons and a daughter. She had gone to the town centre with some friends to celebrate the fiestas organised by the town council and the local hotel and catering industry.