Japan's Mount Ontake erupted on Saturday leaving up to 31 hikers who were caught completely unawares dead.
This incredible footage captured on the mountainside by Kuroda Terutoshi shows the terrifying moment the ash cloud spilled out, enveloping him and his companions.
It's a popular spot for walkers and up to 250 were initially trapped.
"The volcanic rocks fell like hailstones," one man said, according to the BBC.
"We couldn't breathe so we covered our mouths with towels. We couldn't open our eyes either."
The eruption of Mount Ontake