nestled in the wild abundance of the gifford pinchot national forest. in southwest washington. on march 20, 1980, mount saint helens began to show telltale signs that her slumber was ending. >> we are directly over melting helen's right now, there is no question at all that the volcanic activity has begun. you can see smoke -- pouring from the top of the mountain, especially on the north side of the mountain. announcer: a concern for public safety profit the closure of the gifford pinchot national forest. what scientists had anticipated, the irruption of mount saint helens before the end of the century. it had begun. -- the irruption of mount saint helens before the end of the century had begun. it was like any other sunday morning for a four survey treeplanting crew until 8:32 a.m.. announcer: it seemed to happen in an instant. a cubic mile, tons of ash, rock, and ice were rocketed into the stratosphere. the cloud reached nearly 14 miles into the sky. >> in 1940 5, 70 years ago, allied forces liberated not to concentration camps. for the next several weeks on american history