The delays were largely centered around airports in the northeastern U.S. which is among our oldest and most prone systems.
CNN.com reported that all major U.S. airports were affected by the computer problem at a facility near Atlanta. Problems processing data in Atlanta meant that flight-plan information had to be routed through another facility in Salt Lake City.
Now, if you were seeking to create havoc on American airlines, where would you strike?
Those two sites handle all flight plans for commercial and general flights in the U.S.