The dumbest thing I've witnessed is a friend of mine decided to see what would happen if he threw a lit match into a petrol (gas) can and looked in it.
What a moron.
Luckily (somehow) all he lost were his eyebrows and eyelashes...
I saw some retard throw a petrol can into a bonfire surrounded by people ( i decided at that point to move away!). It exploded and shot out at about 80mph in the only gap where there were no people. Looked like the delorean in BTTF. A trail of fire across the parking lot. It was a miracle it didn't explode at another angle..