346 - The 1980 Eruption of Mount St. Helens

On May 18, 1980, at 8:32 AM local time, a major explosive eruption took place at a volcano in southwest Washington State. After months of earthquakes and smaller eruptions, Mt. St. Helens exploded. Over 1,000 feet of mountain was gone in just a few moments. And 57 people quickly died as hot volcanic ash, mudslides, and a fast-moving, incredibly hot cloud of death and destruction tore through miles of forest.