The keyword phrase functions as a noun phrase, where "atentados" (attacks) is the core noun, modified by the date "11 sep" (September 11). The term is the direct Spanish-language designator for the September 11 attacks, a series of four coordinated suicide attacks by the Islamist terrorist group al-Qaeda against the United States on Tuesday, September 11, 2001. The primary targets were the World Trade Center complex in New York City and the Pentagon in Arlington, Virginia.
The attacks were executed using four hijacked commercial airliners. Two of the aircraft, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South Towers of the World Trade Center, respectively, causing their eventual collapse. A third aircraft, American Airlines Flight 77, struck the Pentagon. The fourth plane, United Airlines Flight 93, crashed in a field in Shanksville, Pennsylvania, after passengers and crew attempted to regain control from the hijackers, thwarting its intended strike on a target in Washington, D.C. The total number of fatalities was 2,977, excluding the 19 perpetrators.
The immediate and long-term consequences of these events were profound, fundamentally altering U.S. foreign policy and global security protocols. In response, the United States launched the "War on Terror," which included the invasion of Afghanistan to depose the Taliban regime that had harbored al-Qaeda. Domestically, the U.S. government implemented sweeping changes in national security, including the creation of the Department of Homeland Security and the enactment of the USA PATRIOT Act, which expanded surveillance powers. The event also led to a complete overhaul of aviation security worldwide.
