Austin Post/USGS
- When Mount St. Helens erupted on May 18, 1980, it caused enormous devastation.
- The eruption triggered mudslides, an explosion, and plumes of ash that did enormous damage.
- The death of 57 people led to large changes in how the US monitors and prepares for eruptions.
On May 18, 1980, Don Swanson placed a frenzied call to his wife to let her know that he was OK. "That's nice," she said, unconcerned. She had no idea her geologist husband had spent the morning in a plane flying by an erupting volcano.