Fires are not cause by the mining machines themselves, they're usually caused by non-electrically trained people overloading the electrical capacity of their cables, or people not maintaining their equipment and cleaning the dust out of it.

Well, I have seen GPU capacity burst out in flame, although its not long but if the fire catch something else then its gone..
GPUs are not equal to ASIC mining rigs.
One thing is bugging me about the recent fire: Why is ~5% of the world hash-power all in one place?
Edit: the German news article said the farm used about 5MW, which would only be 10Petahashes/second at most.
I suppose if I want to be unlazy, I can look up how many machines were supposed to be in the facility.
News flash for you!
http://www.datacenterknowledge.com/archives/2014/11/06/knc-miner-to-build-another-20mw-for-bitcoin-mining-in-sweden/Because they can.
Note I do not say do any of the below ideas. I am a peaceful person:And as the wonderful brilliant states-person Sara Palin says lets target them
http://www.harpyness.com/2011/01/08/congresswoman-on-sarah-palins-target-list-murdered-at-political-event/So that is a 30mw plant running 40 to 50ph in hash . So one burned down in Thailand with 6-8ph.
So how wise does having all this hash in one spot look today? I wonder how well they are sleeping in Sweden today?