6.70/10 2006-03-21 60 minutes.HDEruption at Mount St Helens. Rising almost 10,000 feet over Washington State, the volcano had not erupted for more than 100 years until May 1980, when its unexpected explosion unleashed a destructive force estimated to be 500 times the power of the Hiroshima atomic bomb.An: 2006Studio: BBC OnePays: Canada, France, United Kingdom