2011 Sierra Leone 9/11 10th Anniversary Souvenir Sheet

This souvenir sheet was issued by Sierra Leone to mark the tenth anniversary of the September 11, 2001 terrorist attacks, featuring a single stamp depicting the Tribute in Light memorial, two powerful beams that recreate the silhouette of the fallen Twin Towers against the New York City night skyline. The sheet honors all three attack sites, listing the World Trade Center, the Pentagon, and Stonycreek Township, Pennsylvania, the rural site where United Airlines Flight 93 crashed after passengers attempted to retake control from the hijackers. It also names all four hijacked flights, American Airlines Flight 11, United Airlines Flight 175, American Airlines Flight 77, and United Airlines Flight 93.

The Tribute in Light memorial has been reinstalled annually in Lower Manhattan on the anniversary of the attacks since 2002, becoming one of the most recognizable and moving visual tributes associated with September 11. Sierra Leone, a nation in West Africa, joined numerous countries around the world in issuing anniversary tributes, reflecting the global scale of mourning and remembrance the attacks continued to generate a full decade later. The sheet's design incorporates the phrase "Never Forget" alongside its central "In Memoriam" heading, language widely used across memorial observances held throughout the United States on the anniversary itself.