A few weeks ago on a Monday night, I was trying to cook fish sticks at my apartment in Kingston (my university town. So, not at home.) I had never used the oven before, not even last year (always just used the burners) so I wasn't prepared for how small the interior was - the cookie sheet barely even fit in there, and in fact it got stuck a bit and I had to wiggle it to get it in.
That wasn't the mistake. The mistake was that I didn't notice the potholder AND the oven mitts that were...um...hanging right next to the stove, so I tried to use dishtowels to shield my hands. It worked the first time, and when I was getting them out to turn them.
When I went to put them back in, however, it was a different story. I wrapped the dishtowels around my hands and tried to put the cookie sheet back in.
It got stuck.
I couldn't get it in or out. I wiggled it and yanked in vain, but it was completely stuck. I wiggled again, and the sheet TIPPED. The fish fell out and fell on the rack and the element, and the dishtowel came unraveled from my hand and
hit the element and caught fire. 
I yelled a bevy of swear words and shook the towel. Luckily the flames went right out! Unfortunately, in the midst of doing this, my hand it the rack, leaving a nice burn on my finger, which oddly enough didn't even hurt at the time.
Now the flames were gone, but there were still fish sticks all over the bottom of the oven, around the element. For obvious reasons, I was a little scared to stick my hand in there around a piece of metal that had previously been heated to 425 degrees! So I left the oven door open for awhile to let it cool, then carefully extracted them with a fork.
The fish was delicious, if not a little charred. And to this day, my housemates have never asked me why there is a charred hole in the bottom of one of the dishtowels.