On a day when buildings fell, heroes rose: Pentagon employees ran into smoke-filled corridors to guide their friends to safety. Firefighters rushed up the stairs of the World Trade Center as the towers neared collapse. Passengers aboard Flight 93 charged the cockpit and laid down their lives to spare countless others. One of the worst days in 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.