I mean, we probably wouldn't know/be told about it. But assume we did somehow .. you can't really drive anywhere to attempt to get away. Roads would immediately be clogged.

You could setup a tripod and get your camera auto-snapping. Might get a good shot if the camera survives the shockwave. If you want to live, you could lay down in your bathtub or basement and pray. If you have loved owes, probably hold onto them as well.

I live alone and have no basement, but I'm also no where near a major city (closest is Atlanta 2 hours away). So I'd probably sit in the grass, in the part of my yard that doesn't face Atlanta, touch some grass, remember all the people I love and try not to think too much about tomorrow.