Over night a propane depot in Toronto, Canada caught on fire and was burning for a while, and then exploded like you wouldn't believe. Here are some videos you must watch of people that caught it on film:

http://www.youtube.com/watch?v=oV5udSWJcZo

These two videos you can actually see the shockwave emit from the explosion:

http://www.youtube.com/watch?v=Jbw_K8pfNfo
http://www.youtube.com/watch?v=MjsdlBk6PUY

UPDATE: Here is the best view yet:

http://www.youtube.com/watch?v=__1Ym_F94CE