Located on the Juan de Fuca and North American continental plates, when one of the plates went underneath the other plate, it created a 5.1 earthquake that started the process for the eruption of Mount Saint Helens. The volcanic eruption took 57 lives including Mr. Harry Truman who lived on the mountain refusing to leave because his lodge was all he had and he needed to stay back to take care of his place and David Johnston, a United States Geological Survey Volcanologist (someone who studies volcanos) who was on the mountain that morning surveying the area due to the plates subducting in earlier days causing small earthquakes in the area. Mr. Johnston was last heard from the morning calling into USGS in Portland, Oregon letting them know this is it, the mountain is erupting. His body was