This phrase, which translates to "what happened on September 11th," refers to the series of four coordinated terrorist attacks by the Islamic militant group al-Qaeda against the United States on the morning of September 11, 2001. The attackers hijacked four commercial airliners, intentionally crashing two into the Twin Towers of the World Trade Center in New York City, causing both skyscrapers to collapse. A third plane was crashed into the Pentagon in Arlington, Virginia, and the fourth crashed in a field in Shanksville, Pennsylvania, after passengers and crew attempted to retake control.
The attacks were executed by 19 al-Qaeda terrorists. The first two impacts occurred at the World Trade Center's North and South Towers, respectively, using American Airlines Flight 11 and United Airlines Flight 175. The third attack involved American Airlines Flight 77, which struck the western side of the Pentagon. The fourth plane, United Airlines Flight 93, was targeting a location in Washington, D.C., but its mission was thwarted by the actions of those on board. The operation was conceived and directed by al-Qaeda leader Osama bin Laden as part of a declared war against the United States.
The consequences of these events were immediate and profound, resulting in 2,977 fatalities and triggering major U.S. initiatives to combat terrorism. This led to the launch of the War on Terror, including the invasion of Afghanistan to depose the Taliban, which had harbored al-Qaeda. Domestically, the attacks prompted the creation of the Department of Homeland Security and the implementation of extensive new security measures, fundamentally altering airport security, national surveillance policies, and international relations for decades to follow.
