State: The main explosion happened at 8:32 a.m. PDT. 57 people died, 210 square
miles of wilderness were destroyed.
activity had first been recorded on March 20, 1980, and on the 27th March steam
and ash were emitted through St Helen's crater and vents.
explosion was triggered by an earthquake of about 5.0 on the Richter Scale.
north side of the summit began to slide down the mountain and the explosion levelled
everything for about 12 miles in all directions, 10 million trees were felled.