National Geographic invites the viewer to revisit that tragic day in 2001 with a collection of powerful, immersive stories of people who were intricately associated with and impacted by the event: people in the highest echelons attempting to prevent and stop the attacks; ordinary people caught in the middle, like the window washer cleaning the windows of the 93rd floor of the World Trade Center just moments before the attack; and people who still cannot shake how the events of that morning altered their worlds forever.