After climbing towards the volcano, which is known to have daily eruptions, the hikers made a swift turn when debris began to fall. Large clouds of ash could also be seen filling the skies as the hikers ran down El Paso de la Muerte, also known as the Death Trail, according to Storyful.

This makes Etna an enigma. Despite its long historical record – plus extensive monitoring and research in modern times – no known geological process can fully explain how the volcano formed, or where it keeps getting all the alkaline magma for its frequent eruptions.

How scientists risked everything on a completely untested, wildly destructive tactical operation to forcefully alter the course of nature.