That doesn't look good...

Can you please tell me the scenario this might happen? I never leave my machine overnight running, never have.. not for fear of this, but just for fear in general lol..

I run pretty much all my gear on limiting devices, so pretty much everything runs of an independant circuit breaker, and the house has a thermal fuse set. Would a circuit breaker not detect a thermal runaway? I have never had a mosfet fail and blow on me, but it looks pretty violent.. I assume you did this outside with a 12v DC power supply and no breaker? have you tested it with one?