Five months previously, Juan Alberto Alonso had obtained an administrative position at the Offices of the Social Security. Three months before, he and his wife had adopted a little Spanish girl, Sara. On March 11, the couple had another important appointment: they were due to meet a psychologist to assess their suitability to begin the process of adopting a brother for Sara. Juan Alberto Alonso was travelling on the train that exploded at Atocha station. He was taken to the La Princesa Hospital. His parents travelled from Cáceres to be with him, but on their arrival, they were informed that their son had already died.
11 March 2004 fell on a Thursday. Early that morning, a number of terrorists with links to Al-Qaeda planted thirteen bombs on four suburban trains covering routes running through Madrid. Ten of the bombs exploded between 7.37 and 7.39 am, when the trains were at Atocha, El Pozo and Santa Eugenia stations and alongside Calle Téllez. 191 people were killed in the attack and around 1,500 were wounded. It was the deadliest terrorist attack in Spanish history. On 3 April 2004, agents from the Special Operations Group (GEO) were about to enter an apartment in Leganés where the perpetrators of the attacks were believed to be hiding when the terrorists detonated twenty kilograms of explosives in an act of collective suicide. The ensuing blast killed one of the officers, bringing the total number of people killed by the 11 March bombers to 192.