Cristina accompanied her father to hospital where he died. The horror transformed this middle-class, unpolitical Basque teenager into a campaigner who has persuaded tens of thousands to overcome their fear of Eta violence. She pioneered a pacifist movement that demonstrates silently against Eta gunmen several times a week throughout the Basque country. Last week she was nominated for the EU's Women of Europe prize.
After Enrique's death, Cristinas's mother had a nervous breakdown. Her sister Irene was only 14. Cristina abandoned journalism studies and took a job at Telefonica herself to support the family. "Fellow Basques killed my father supposedly to improve the conditions of other Basques, and had made us victims," she says. "This thought obsessed me."
She talks with an intensity lightened by humour, showing no trace of the hatred she says dogged her for years. "Every time they announced the death or torture of an Eta member, I rejoiced. I couldn't forget. My friends found me impossible. But one day I decided I didn't want to keep on hating."
The turning point was the disappearance of an Eta suspect, Mikel Zabalza, detained in 1985 by the Civil Guard and later found face down in a river. "Statements by Mr Zabalza's mother affected me deeply. We were on opposite sides of the trenches, but I realised her grief was the same as mine and for the same reason."
Cristina resolved to seek reconciliation, and to encourage victims of violence to become more active. "At that time ordinary people kept quiet about what was happening. Everybody was afraid of reprisals. You might have an Eta sympathiser living next door."
In 1986, now 24, Cristina attended a conference on the media and violence and, trembling, appealed to fellow victims, including Mr Zabalza's mother, to join her in a process of pardon and reconciliation.
Within two months, she received 3,000 letters of support and organised a meeting of those who had suffered on both sides of the Basque conflict.
"People began to gather together and overcome their fear, and these were the seeds of today's peace movement." Cristina devotes her life to the campaign, but still works at Telefonica. Her team offers support and professional help for "people threatened by Eta or beaten up by the police", and tries to promote its message in schools. "But it is difficult because the teachers are divided and pro-Eta youth groups are well organised."
Radical young Eta sympathisers hurl stones and insults at the peace demonstrators, who wear a blue ribbon and assemble with increasing confidence in San Sebastian and other Basque cities, calling for the freedom for Jose Maria Ortega Lara, a prison officer kidnapped in January, and Cosme Delclaux, a local businessman seized last month for not paying "revolutionary tax".
"An indirect confrontation constantly floats in the atmosphere, but many Basques are no longer prepared to accept in silence that Eta kidnaps people in their name," Cristina says.
What about her personal life? Her face collapses with laughter. "I fell in love with the son of my father's predecessor who was assassinated, and we've been together seven years. Inaki and I haven't had time for children yet. But we will."