In 1980, following a weeklong series of earthquakes and smaller explosions of ash and smoke, the long-dormant Mount St. Helens volcano erupted in Washington state, U.S., hurling ash 15,000 feet into the air and setting off mudslides and avalanches.
An earthquake at 8:32:17 a.m. on Sunday, May 18, 1980, caused the entire weakened north face to slide away, creating the largest landslide ever recorded. This allowed the partly molten, high-pressure gas- and steam-rich rock in the volcano to suddenly explode northwards toward Spirit Lake in a hot mix of lava and pulverized older rock.
Approximately 57 people were killed directly. Hundreds of square miles were reduced to wasteland, causing over a billion U.S. dollars in damage, thousands of animals were killed, and Mount St. Helens was left with a crater on its north side.
Lakes nearest to Mount St. Helens have been partly covered with felled trees for more than thirty years. This photograph was taken in 2012.
For more information visit:-
https://en.wikipedia.org/wiki/1980_eruption_of_Mount_St._Helens