9. Mount St. Helens, Washington, USA
May 18, 1980, was a bad day in Washington state.
Silent for over 100 years, the picturesque 9,677-foot peak had by late April grown into a bloated, trembling blister of rock and magma. And like a blister, it popped early on a Sunday morning, rocketing fiery ash out to the north at close to the speed of sound.
The eruption killed 57 people and did almost $3 billion in damage when all was said and done. It also lopped 1,314 feet off the height of the mountain, which was reduced to a smoldering crater.
This was the most deadly volcanic eruption in Unites States history -- and it was just a pipsqueak, really.