The Here And Now

 ...stay put. Shelter in place. Unless it is a fire, a flood,  tsunami or hurricane and you are told to evacuate.  Even for  low level nuclear bomb detonation they recommend you stay in place for at least 24 hrs (this assumes you are outside the blast  and heavy radiation radius).  The same is true if you are lost in the woods or your car breaks down in a national park.

So stock up on food and water for 72 hrs. If toilets are not working, then store your emergency supplies in a large 5+ gallon paint can, with 2++ heavy duty garbage bags and a box of kitty litter. A bottle of bleach is good.