Maybe that's some of the new common core math where "feelings" enter into it :-)

Real old school math is hard mathematical facts that just are simple black and white not shades of gray, interpretations , feelings or wants it simply is what it is.

I will liken all these potential black swans out there to all the nukes around the world sitting quietly in silo's any one at any time could be the triggering event.

Depending on ones location nearest the blast once you see the fireball it's mere seconds before the shockwave hits and the radiation begins to burn. 

https://www.youtube.com/watch?v=-s8iie0zZ-g

There is no way to out guess or out run anything at that point if preparations have already not been made.