Spent grain explosion

Due to a hangover, I got a late start on yesterday's brew session and by the time the wort was in the fermenter, it was over 100 in the garage and I had no motivation to finish cleaning up.

When I walked into the garage this morning, there was an interesting smell coming from the MLT, which I expected. However, I didn't expect the aftermath of what looked like a small explosion. There was grain all over the inside and outside of the MLT, and a fair amount on the floor and the shelves in the area. Didn't quite reach the ceiling though.

http://yogensha.net/gallery/main.php?g2_itemId=3512

I've never had a fermenter blow up, so I guess this is my payback

 

Whoa! I have never heard of this happening. Now I just throw all my spent grains on the lawn while chilling the wort. Seems to green up the grass pretty well.