Sorry, all flights grounded because solar flares. At least we only lost 20 planes this time.
Sorry, all flights grounded because some fuckwit decided to use satellites for a network instead of fiber underground and a bad actor jammed the radio spectrum.
Sorry, all flights are grounded because Elmo Muskrat got in a pissy fit on Twitter with a 15 year old kid, and he showed him by shutting off the satellite network over the US. (Variation on your last bullet.)
You think that's crazy, check out Leadville, Colorado. (3,095m)