Here in urban Los Angeles, most SHTF situations we've faced were vastly overrated. Earthquake, riot, wildfire get lots of airplay, but have surprisingly little effect on the majority of people.

Outside a really large earthquake, or a terrorist attack of extremely large proportion, the best thing to do is not freak out.

Terrorism threat should be put into perspective. Even if the US managed to sustain a 9/11 sized casualty amount from terrorism once a year, one's chances of dying by terrorist would still be dwarfed by one's chances of dying in a traffic accident.