What event is commemorated by the memorial at the site of the former Twin Towers?

The memorial at the site of the former Twin Towers commemorates the September 11 attacks, which occurred on September 11, 2001, when terrorists hijacked four commercial airplanes and carried out coordinated suicide attacks against significant American landmarks, including the World Trade Center in New York City. The memorial, known as the 9/11 Memorial, pays tribute to the nearly 3,000 victims who lost their lives that day, as well as to the first responders and rescue workers who risked their lives to save others. The site stands as a somber reminder of the tragedy and loss experienced by families and the nation, while also symbolizing resilience and hope in the face of adversity. This specific focus on the September 11 attacks distinguishes it clearly from other historical events such as World War II, The Great Depression, or The Cold War, which are not directly related to this memorial.