TIL that the army built a tunnel to drain Spirit Lake, to relieve water pressure against a natural dam created by the eruption of Mount St. Helens. If the tunnel fails - and it will - the dam will fail and a 40-foot wave will race down the valley, all the way to Kelso, WA, on the Columbia river.

https://www.opb.org/article/2024/10/26/spirit-lake-mount-st-helens-skamina-…
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1ggvque/til_that_the_army_built_a_tunnel_to_drain_spirit/