The catastrophic collapse of the north face of Mount St. Helens on May 18, 1980. Photographed by Gary Rosenquist, 11 miles northeast at Bear Meadow.
Mount St. Helens is one of 169 active volcanoes in the US, most of which are in Hawaii or Alaska, and eruptions happen every year, For a long time Mount St. Helens was considered dormant until in 1980 when it erupted.
When it erupted it was rated a 5/8 on the Volcanic eruptive scale, which is about average. The only other eruption in the 48 states before Mount St. Helens was the 1915 eruption in Lassen Peak.
57 people died in the eruption and 2 billion dollars in damage in 1980 is which after inflation results in 5.7 billion dollars in damages.
Ever since the eruption in 1980, there have been several earthquakes and documentation of magma flow.