I haven't really burned sth special, but I was working in a chemistral laboratory and there were several accidents... Well, I think you all know the reaction of Natrium and Water for example ?!? While we were cleaning the laboratory on the last day (as usual) we just tried to neutralize the Natrium with Isopropanol; we thought it was gone and then started to neutralize some other things which were in there with water... And suddenlty the laboratory hoot was a bit at flames! But there did not happen anything more. Our assistant caught up the fire-sand and got it under control.
At the other times there were looots of thing where something could happen, but just went well normally...
Some other story: When my brother and I were young we built caves in our rooms... E.g.under the desk etc. Once we had our bedside lamp a little bit too near at the rug, and it starts to smell, but we checked immediately so that no fire could begin!
-Aredhel