I was out flying, had a customer on a photo shoot. While doing such flights around a major city, I always keep one radio tuned into regional approach so I can listen to the other airplanes flying near us.
First thing I heard that told me something was wrong was an airliner reporting that he just heard from his company that there had been a crash of some kind in New York. We all assumed it was an accident of course. Within a few minutes, ATC (air traffic control) got on the radio and said "we have a national emergency in progress, everyone just stand by and stay off the radio". A few seconds later they came back and said "All airliners, please secure your cockpits".
I remember thinking, damm, that's weird, they don't say things like that. What on Earth is going on?
Another minute, ATC came back on the radio and said "attention all aircraft, the FAA has ordered the National Airspace System shut down due to the national emergency in progress. All aircraft are ordered to land at the nearest airport. Any noncompliance with controller directions will constitute an attack on the United States and fighters will be scrambled."
Nothing but silence, I don't think anyone could believe it. I almost thought they might be kidding, but ATC does not joke about such things. Someone came back on the radio and said, "can we cancel our IFR flight plan and continue VFR?". The controller replied, "this is for all aircraft of any type, any flight plan, the United States is under attack by unknown forces, any aircraft refusing to comply with instructions is subject to being shot down by fighters."
Not another arguement from anyone, we all followed instructions and got everyone down within 30 minutes or so. I landed about 15 minutes after that last ATC warning, shut down and went into the hanger and turned on the news. I couldn't believe it, I was in shock.
Grasshopper