Astronauts return to earth and find it empty. They’ve missed the second coming of Jesus by four years.

(from Wastelands)

Now that’s an old school apocalypse: Everybody’s gone, leaving our befuddled astronauts to contemplate their next move. Do they try to signal God, now that they know he’s real? Do they try to repopulate the earth? They were mostly atheists when their mission began. Now they wander the vacant Earth, having some hilarious discussions and feeling a weird sense of loneliness.
What Happened: Well, according to the old newspapers blowing around, Jesus, who is real, came back and took everybody, living and dead up to Heaven, which is also real.
Destruct-O-Meter: 5. I mean the people are gone, but the planet seems to be on the rebound.

Earth is a bleak wasteland and all the kids in the habitat pin their hopes on Artie the bike-maker.

(Wastelands)

There’s something sorta classic about this thing, the kids on bikes darting around the decaying urban wasteland and dodging the various gangs and corrupt authorities. And the end has a sort of comic book mythology vibe to it. I remember liking this story but it’s been a while since I actually read it.
What Happened: I believe it’s an ozone or nuclear thing, with the earth’s unsheltered surface basically becoming uninhabitable due to radiation. Humans are either escaping the planet or hiding out in enormous, mostly lawless habitats. That said, this is not a horror story. More straight up adventure.
Destruct-O-Meter: 7. Everybody out of the pool.

Tracing the apocalypse back to its tipping point.

(from Wastelands)

I wish there had been a war, a plague or some new, grand Chernobyl. Something we could point to and say, “That’s it. That’s what killed the world.” But it wasn’t like that.

This is a short one.
What Happened: It’s kinda funny, but told with a sigh: A fender bender makes somebody miss a meeting, making somebody not send some fax, and on and on until, yep, everything falls apart. Kinda like the riot in Police Academy.
Destruct-O-Meter: 5.

A dad and his ageless mutant daughter travel around with their mutant animal zoo, trying to make some cash.

(Wastelands)

Trevin noted with approval the endless stretch of ten-foot-tall chain-link fence between them and the river. Who knew what god-awful thing might come crawling out of there?

O-Forms are original form animals, which are becoming rarer and rarer in this age of tigerzelles and crocomice. They seem kinda harmless and, in Trevin’s eyes, sort of unremarkable. I guess everybody’s starting to look at things that way, which is why the zoo/sideshow gets very few visitors. Caprice, the toddler with the adult brain, is the freakiest thing here, and I don’t blame her dad for being totally creeped out. This one’s a bit short to blow me away, maybe, but fascinating in its way. You can read it here (in some mutant cached version).
What Happened: Some chemical event is causing most living things (but not insects) to mutate. We don’t know the exact extent of it — how much it affects people — until the end of the story. But I guess this evolutionary apocalypse is bigger than I first thought.
Destruct-O-Meter: Only 4, but the end is near.

It’s the end of the world as we know it and the only people who survive at the sysadmins called to their server rooms when it all goes down.

(Wastelands)

Best story in this all-armageddon book so far. Why? Onpage apocalypse. As in: We get to experience it happening. All the other stories so far were this-is-the-strange-new-world kinda thing, where all the death and destruction were in the past, usually waaaay in the past. Okay, it’s told from the perspective of a bunch of tech nerds trapped in a building and interacting via IM with out nerds similarly locked away from the disaster, but still. It’s all normal that morning and then, soon enough, the world is unrecognizable. I really dug the author’s unflinching use of IT lingo, most of which I didn’t know but was able to glean from context. A totally fun and entertaining and inventive story.
What Happened: A computer virus attacks the web. Real virus attacks the people. Something’s blowing up buildings. Craziness.
Destruct-O-Meter: 5. It’s a thorough armageddon — three levels deep — but people are still out there getting by, in a way.

After burying another member of their expedition, Chaka and Quait decide to turn back.

(from Wastelands)

Then Chaka meets somebody she guesses is a ghost, but is most likely an old amusement park attraction (some kinda fancy interactive hologram, most likely). Neither one seems to recognize each other’s world, because so much time has passed. I really dug this story: weirdly fascinating but kinda subtle. Awesome.
What Happened: One way or another, civilization has mostly collapsed. There are plenty of ruins, but no one seems to have much connection to them or the way earth used to be. What specifically went down isn’t clear.
Destructo-O-Meter: 8.