This page is about military and government exercises which were in progress when the first plane hit. At least one simulation was eerily similar to what actually happened. The combination of these two facts caused confusion amongst the fighter pilots and ground crew, as many weren't sure what was real and what was simulation. It also may have meant that the fighter jets were not within easy reach of the areas they should have been able to defend within minutes (New York City and Washington, DC).
Note: This description needs to be checked against available news stories, and the news stories need to be tracked down to their sources.
- 2004-05-31 New bombshell: on 9/11 Pentagon conducted live-fly hijacking wargame: hearsay, but close to primary source: “This was one of five wargames/simulations on the morning of 9/11, many with confusingly similar names (the confusion no doubt intentional): "Vigilant Guardian", "Northern Vigilance", "Vigilant Warrior", etc.”
- On 9/11, CIA Was Running Simulation of a Plane Crashing into a Building
- 2002-08-24 9/11, CIA Simulation-Plane Crashing into Building: commentary