On a day when buildings fell, heroes rose: Pentagon employees ran into smoke-filled corridors to guide their friends to safety. New York City Fire Department|Firefighters rushed up the stairs of the World Trade Center (1973–2001)|World Trade Center as the towers neared collapse. Passengers aboard United Airlines Flight 93|Flight 93 charged the cockpit and laid down their lives to spare countless others. One of the worst days in United States|America's history saw some of the bravest acts in Americans' history. We'll always honor the heroes of 9/11. And here at this hallowed place, we pledge that we will never forget their sacrifice.