Worst case scenario would be roving mobs of looters... armed. There will be no LE available to help you out.
Save the last bullet for yourself... section9.
I've always believed that we're made of sterner stuff than that.
Don't underestimate people with common sense. That's what the 2A is all about. Quarantined areas will exist, period. That's just a fact of life.
My scenario posits a fifth column of trained AQ saboteours and terrorists. Remember, AQ has had years to prepare.
It is advisable to plan as if LEO is paralyzed for a short period of time, or is somehow preoccupied. How and ever, 'tis best to stay safe.
Be Seeing You,
Chris