I was just going back into the sector at work (air traffic controller) when I passed a TV monitor where a few guys were commenting on a plane that had just hit one of the towers. I assumed it was a smaller type aircraft.
I did a short stint in the sector working low altitude traffic in the Grand Island (GRI), Omaha (OMA), Nebraska sector. Before being relieved from the position a "ground-stop" had been issued that forbid us from releasing any additional traffic into the system. I had no idea then that the ground-stop was related to the aircraft that hit the tower. The supervisor that gave the order wasn't clear as to why. I just did what I was told then went out on break and saw for myself the reason why. Twenty minutes later the order to get all the aircraft on the gound was issued and the airspace soon was empty with the exception of some military aircraft spinning circles over some of the more populated areas.
A few hours later Air Force 1 (the president's aircraft) came through my airspace and landed at Offutt Air Force Base. The interesting thing about it was that the aircraft's data tag wasn't the typical data tag we'd use to track an aircraft, rather, it was void of anything identifying it as Air Force 1. We used only a discreet 4 digit transponder code.
Kevin g
https://youtu.be/bo1ZtpKqlYw