"One Second After" by William Forstchen. Recently published novel about how a small town in North Carolina handles life after the USA being hit by 3-ish exo-atmospheric nuclear detonations.
Denial runs strong early on. Seriously, if I were on my cell-phone talking to an old friend/former CO who is now at the Pentagon and hear background noises including yelling/screaming/arguing and the General says, "Something just came up, I gotta go-" and the call drops *AND* the cell phone goes dead *AND* the electricity to the house dies ALL AT THE SAME TIME, I'm NOT gonna be hoping things get better tomorrow. Hell no. I won't even bother checking to see if the land-line is working. At that point, EVERYONE puts on a gun ALL THE TIME, trees get dropped across the road, etc etc. Because, my friends, at that point, the shit has indeed hit the fan and we are ALL downwind...
Thankfully, it is just a work of fiction.
For now.