On May 18, 1980, Mount St Helens blew in the US state of Washington. The eruption, which measured 5 on the Volcanic Explosively Index, has been declared as the most disastrous volcanic eruption in modern US history. A huge 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.
Now scientists fear it could happen again.
Dr Donald Swanson, who works for the United States Geological Survey (USGS), witnessed the aftermath of the last explosion.
He described the apocalyptic scenes he witnessed two days after the main event on Amazon Prime’s “Mega Disasters” documentary.
He said in 2006: “It was like walking on the moon – I have never seen anything like it.
Dr Swanson sent a warning to his fellow Americans (Image: AMAZON)
