A huge volcano in Russia started to erupt on Tuesday, triggering a series of emergency warnings. The Shiveluch volcano in Russia’s far eastern Kamchatka peninsula spewed out an ash cloud that climbed over 12 miles high, carpeting surrounding villages in a layer of gray ash over 3 inches thick—the deepest in 60 years. The cloud covers an area of almost 42,000 square miles, according to the Kamchatka Branch of the Russian Academy of Sciences’ Geophysical Survey. No casualties have been immediately reported, but the Kamchatka Volcanic Eruption Response Team issued a red notice for aircraft flying in the region, and locals have been warned of mudflows caused by lava melting snow on the mountain. Oleg Bondarenko, head of the Ust-Kamchatsky municipal region, said some schools on the peninsula had to close and residents were ordered to stay indoors.