In response to the attacks on September 11, 2001, the FAA orders all planes out of the air. American and Canadian air traffic controllers face a difficult situation: how to safely re-route and land 6,500 planes carrying close to a million people. For individual air traffic controllers, the work is chaotic, intense, and deceptively simple: pick a new route for each flight; radio instructions to turn; listen for pilot confirmation; hold traffic to keep airways from overcrowding. From Cleveland, Ohio to Gander, Newfoundland and Labrador, controllers on September 11 searched for alternate airports to land large jets as their traumatized colleagues return from breaktime having watched the attacks on TV.