24 Years Ago in TIME

After several days of small earthquakes, MOUNT ST. HELENS erupted late last week. When the mountain in Washington State exploded back in 1980, TIME recounted the devastation in a cover story.

"Vancouver, Vancouver, this is it!" The frantic warning was radioed at precisely 8:31 a.m. on that fateful Sunday by Volcano Expert David Johnson, 30, who had climbed to a monitoring site five miles from Washington State's Mount St. Helens in the snow-capped Cascade Range, 40 miles northeast of Portland, Ore. He wanted to peer through binoculars at an ominous bulge building up below the crater, which had been rumbling and steaming for eight weeks, and report his observations to the U.S. Geological Survey. Seconds after his shouted message, a stupendous explosion of trapped gases, generating about 500 times the force of the atomic bomb dropped on Hiroshima, blew the top off Mount St. Helens. In a single burst St. Helens was transformed from a postcard-symmetrical cone 9,677 ft. high to an ugly flattop 1,300 ft. lower ... Johnson was never heard from again. --TIME, June 2, 1980