Mount St Helens volcano WARNING: Scientists ‘closely monitoring’ eruption activity

On May 18, 1980, Mount St Helens erupted in the US state of Washington. The blast, which measured 5 on the Volcanic Explosively Index, has been declared as the most disastrous volcanic blast in modern US history. An eruptoon column rose 80,000 feet into the atmosphere and deposited ash in 11 states, killing at least 57 people and causing more than $1billion (£770million) in damage.