Pornokitsch

1) No. And this one is something Anne and I bandied around together, and I think it is the 'rightest' answer.

It helps that disaster fiction is set in our world for empathy, but what's more important is that the disaster follows understood natural laws. In a fantasy world, there's too much room for magical / inexplicable / impossible intervention - and, even if that doesn't happen, the reader expectations are still shifted. What's fundamental to disaster fiction is that there is no 'divine intervention', it is humans versus a failing system. If that possibility even exists in the mind of the reader, the story won't work.

2) Maybe. I think there are a few isolated episodes of disaster fiction within fantasy.

For example, the volcano episode in KJ Parker's Pattern, or the plague in The Folding Knife. What's notable there, I suppose, is that those are both Parker books without any magic in them. In fact, if anything, those are both books in which Parker is rather firmly establishing traditional natural laws.

Another example - possibly because it can be used as an example of anything - is Miéville's Perdido Street Station. The city is a complex system, the Slake Moths are the flaw, and, as is traditional for the disaster genre, everything goes to hell at the halfway point. The problem here is twofold. First PSS is no more or less disaster fiction than it is anything else - from paranormal romance to hard SF. Miéville's work is Miévillian, and no other genre. Second, Perdido both works and doesn't work as disaster fiction because of the way it adheres to non-science. Calling it "magic" isn't really right: Perdido feigns a system, but, at the same time, abhors it. There's a lot of deliberate hand-waving and magician's force, but that's a distraction from the fact that the non-science can do anything, at any time. Perdido and Bas-Lag seem to follow logical rules, but they actually very much do not. So, in a sense: yes, Perdido shares some of the aesthetics of disaster fiction, but, underneath the surface... not really. It walks and talks like a duck, but it is really a duck-shaped lure on the dangling probiscus of a deep sea monster.

3) "Yes". Possibly the problem with trying to spot disaster fiction in fantasy is that most fantasy is too rural. Airport, The Glass Inferno, etc, all rely on complex systems with population density: it may be semantic, but that's what makes it a disaster and not an isolated tragedy. Being that most of the fantasy that I read is still stuck in the pseudo-Middle-Ages-European style, everyone is simply too dispersed.

But what if you extend the geographic boundary? So, for example, what if the entire world were a single system, threatened by a single disaster? Traditionally, this would immediate throw the book into science fiction (see: every book by Charles Eric Maine). But in epic fantasy, reducing all the world's problems to a single point is the stock in trade.

Let's take, for example, The Lord of the Rings. We have a status quo: the bucolic country squireness of the Shire, the feudal utopia of the human lands, the artisan al spirituality of the Elves and Dwarves. This is firmly established (with a heavy focus on the Shire) throughout Fellowship. But, as with the fire in The Glass Inferno or the terrorist in The Explosion, our scenes of the system in beautiful balance are undercut with fragments of 'that ain't right'. Black riders. Troll migrations. Orc sightings. If the delicate harmony of Middle-Earth is maintained properly, these things don't happen. But something is wrong here, and even as most people try to ignore it, a few desperate doom-sayers have spotted the impending disaster. (See: Saruman as the greedy land developer in Condominium.)

And, indeed, it is the series' midway point where the disaster strikes: Sauron invades. And the rest of Middle-Earth - that invulnerable system that we now know is fatally out of whack - crumbles. In Gondor, the civil service has taken over. In the Shire, industrialisation. In Rohan, political corruption. Everywhere, Orcs. OH IF WE HAD ONLY LISTENED.

The final part is the reaction to the disaster, and, boy, is Middle-Earth lucky to have had those monarchist-eco-warriors ('eco-conservatives'?) in place. They throw the widget in the wodget (flip the master switch, which is at the bottom of the flood/fire/terrorist camp) to purge the evil and then devote themselves to mopping up the little problems. Industrialisation is purged. The monarchy is rethroned. Princes marry princesses. Orcs are killed. We return to the glorious summer days where we began.

This is just one - slightly ridiculous - example. But it does work.Two fundamental conceits of epic fantasy are that a) the Gaia complex: the world is one connected organism or system and b) all evil can be reduced to a single point. The world is dying. Find the evil one and hit him with a sword. Reset. The major flaw with the disaster fiction / epic fantasy parallel is that most epic fantasy, a la Tolkien, resets - the end result is a return to the status quo. Disaster fiction is more Hegelian: after the disaster, the world has changed - it stabilises, in a new place.

This perhaps, leads us back to our initial problem with "disaster fantasy": only in a magical fantasy world can problems be simply... reverted and, often, simply forgotten. Disaster fiction books are all united by how they serve as a warning - against hubris, carelessness or simple human frailty. Epic fantasy carry no such warning, because the world doesn't move on - it merely reverts.

4) Yes (potentially). So, from the above, you'd need... population density, a disaster, a series of creative challenges dealing with survival and recovery, natural laws (or magical laws that are extremely consistent and instinctively accepted by both reader and author) and some sort of fallout/result (e.g. it can't just revert and be forgotten). I'm not sure if that exists as a fantasy book, but as a RPG scenario, it would be perfect. 

So, in conclusion: no (probably) but also maybe (but not really), "yes" (in a way) and yes (theoretically).

I suppose the most interesting point, long-term, is the "yes" - not as an answer to the initial question, but as a cross-genre lesson for epic fantasy. It isn't "can there be fantasy disaster fiction?" but "how can we make disaster in fantasy more realistic / tragic / meaningful / well-written?". (I suspect that horror genre learned that lesson a long time, whereas SF still hasn't. But that's a spurious theory for another blog post.)