You know how Pompeii was destroyed in an instant from the eruption of Mt. Vesuvius?  What did all of the damage and the amazing preservation is what’s called a pyroclastic flow.  It’s a very fast-moving conglomeration of ash and gasses and lava that has immense destructive powers.  It’s one of those things that happens so quickly, you don’t have much time to document it.  Luckily, scientists are getting a lot better at predicting volcanic explosion so there’s usually a camera or ten around to capture the awesomeness.  Here is an example of said awesomeness:

[youtube http://youtu.be/95bYATFIOxs]