Australian perspective for part two: Australia is really big. We do backburning (controlled burns) every single year, but it's nigh impossible to get every single area. The Blue Mountains, which had bad fires late last year, gets regular backburning, but it's a very very large area of dense forest (dense EUCALYPTUS forest, which is highly flammable!) and it's hard to control. The Black Saturday fires in Victoria a few years ago were also in an area that hadn't seen backburning in quite a few years.

There's also the fact that it's impossible to predict WHERE the fires will be. Lightning can strike anywhere. Arsonists regularly start fires - one of the Black Saturday fires was arson (I personally think that the arsonist should be charged with murder, incidentally - eleven people died in that complex, and the fucker was only charged with one count of arson causing death!).

We do take as many precautions as we can - fire safety is drilled into Australian kids from a young age, there are building material restrictions (we couldn't use wood on our back porch because we were in the 'flame zone', for instance), we're taught what to do when the fire approaches - but when it's that huge, and when it's in areas that may not be brand new and DO have flammable materials, there's pretty much nothing you can do but get out as soon as humanely possible.