Bear witness to the usual here:
1) Shopping malls are packed.
2) Traffic is as bad as ever. Maybe $4 gas loosened it a bit (and I mean cut a 2 hr traffic jam to 1.5 hr...) but then it snaps back to the usual horrid.
3) House prices have tumbled... oh maybe 5% and going up again.
4) The main refinery in Carson is at 100% capacity.
5) Road construction is EVERYWHERE. 3 am traffic jams are even more horrid than the morning commute.
Just like mainland USA wasn't touched in WWII and the casualties of north Americans were negligible compared to, say Russia, China and Poland, I believe nothing of importance will happen in SoCal.
Sure large swath of the planet will become like a cross between Mogadishu and Kabul, spiced with a bit of Congo Republic... but here, we are simply too wealthy to care.