When incredibly hot lava hits extremely cold snow, it can result in a phreatomagmatic eruption, sending ash, steam, and rocks exploding into the air. On Thursday, this rare event took place at Italy's Mount Etna, sending onlookers running for safety.
At least 10 people were injured by flying debris, including tourists, journalists, and a scientist. A BBC News crew was filming Europe's most active volcano when it spewed out lava and and steam that reached temperatures of more than 1,800 degrees, and journalist Rebecca Morelle wrote on Twitter that a "volcanologist said [it was] the most dangerous incident experience in his 30 years," adding, "Running down a mountain pelted by rocks, dodging burning boulders and boiling steam — not an experience I ever, ever want to repeat." Morelle also tweeted a photo of her colleague Rachel Price's jacket, which had a "massive hole" in it after rock burnt through it. Catherine Garcia