I was a consultant designing and developing training for a client (Frito Lay). I was going to be late to work and called my boss to tell her. She was at D/FW airport and couldn't take off. No one got any work done. The weirdest part was driving home south down the tollway and realizing how eerily quiet it was, because there was nothing flying. That is, except for a lone, low F-16 I saw humping fast not on a regular flight path towards the airport.