At around 6.30 am on 19 March 1992, a member of ETA called the Royal Automobile Club of Catalonia to report that a car bomb had been planted in an unidentified location on the A-18 motorway. He warned that the vehicle would explode between 8.45 and 9.00 am that morning. The vehicle was parked in an underpass on the A-18, close to the town of Sant Quirze del Vallès. While the security forces were trying to locate it, building labourer Antonio José Martos Martínez, who was on his way to work, passed next to the car at approximately 7.55 am. The bomb exploded, killing him instantly.
Antonio José Martos Martínez was a member of the Communist Party of Catalonia and the trade union Comisiones Obreras. He lived with his partner and their daughter in Sabadell (Barcelona). On 20 March 1992, his party, his trade union and the town council of Sabadell, organised a civil tribute to him.