I have realized that zombies are my #1 end-of-the-world scenario.
I live in a geologically stable area, far from oceans and major centres which could be stuck by nukes/terrorism/mass riots/likely invasion. But, see, it only takes a few walking-dead people to wreck a lot of havoc. I figure if 10% of the local population (roughly 220,000) was zombie-fied ... I'd be fucked. Then all the people who live in gated communities would laugh their asses off at me. Unless they were zombies too. Then they wouldn't be able to get out and I could laugh at them a bit, because I really hate those gated communities.