Two Franco aircraft seized and bombed Otxandio for 25 minutes while celebrating the Santamaña holidays. The town square was filled with militiamen, soldiers and civilians and 61 people died, three civilian quarters. They killed, among others, 16 babies under the age of one.

The soldiers of the town faced the attack from the church bell tower, but they could do little. It was the first bombardment of the 1936 war, which preceded the massacres that the Francoists would carry out without scruples.

In the territory controlled by the Basque Government there were no Republican aircraft, so the bombings of military aircraft supporters of the Francoist side would condition the war for the despair of the Gudaris.