Thank you for including the other Continental hubs. You are correct about the airports you mentioned as being international ports of departure/arrival for overseas flights. I didn't know they were also hubs for Continental.
This makes it somewhat easier to sort out what airports may have been the targets for 10 aircraft. How many times have documentaries on Al Quida (sp) mentioned how patient these people are in regard to planning and effecting their terror plans. Just when the world starts to get comfy with flying again....