Carrero Blanco was killed in Madrid by ETA's Txiki command. After Franco's next death, he was the most important political figure in the state. The attack was called Operation Ogro.

For five months the tunnel was drilled under a street that was driving to Mass every day. As they passed over, the artifacts located in the tunnel were cracked and expelled in the air, giving a strong blow to the Franco regime.

It was ETA’s first armed action outside the Basque Country and gave international prestige to ETA, initiated a few years before the celebration of armed acts.

ETA gave a press conference at the Talac in Bordeaux, so the owner was arrested: Member of the Typical Congress of the signatories of the creation document of Edur Agirre, Kataide, ETA Bost.