A recounting of the air defense procedures taken by the United States' military on September 11, 2001. When the unimaginable happened on September 11, 2001, 14 fighter planes took to the skies to carry out one urgent order: go to Condition Air Traffic Zero - clear the skies of all non-military aircraft. In less than three hours, those 14 planes were able to ensure the safe landings of the approximately 4,826 commercial and private planes that were in the air as the horrific events of 9/11 unfolded. Takes you behind the scenes of history in the making with personal accounts from the fighter pilots, Speaker of the House Dennis Hastert, Transportation Secretary Norman Mineta and others.

Originally produced for BBC news in 2002.