Answer:
9/11 and the Madrid Train Bombings in March of 2004
Step-by-step explanation:
The attacks of 9/11 were a series of four coordinated terrorist attacks performed by the Islamist terrorist group Al-Qaeda. Two hijacked airplanes struck the World Trade Centers in New York City, causing the towers to topple and kill 2,977 people.
The Madrid Train Bombings were two almost simultaneous bombings done to the CercanÃas train system in Madrid, Spain, three days before the country's general election. The attacks killed almost 200 people and injured nearly 2,000. The Spanish judiciary found that Al-Qaeda directed these attacks as well, although no cell of the terrorist group has claimed the attacks. But the Partido Popular (PP) political party in Spain accused their opposing party, the Spanish Socialist Worker's Party of conducting the attacks since the main candidate of the PP lost. The PP also claimed they had evidence that a separatist group was responsible for the bombing as well.