On this day, May 18, 1980 - the destructive eruption of the Mount St. Helen's volcano in Washington State took place.
Info Link - https://www.theatlantic.com/photo/2015/05/the-eruption-of-mount-st-helens-in-1980/393557/
Displays with ash samples available - http://galactic-stone.com/mount-st-helens-volcano-eruption-display-genuine-ash-sample/
Image credit : Wikimedia Commons.