Mount Vesuvius spawned a deadly cloud of stones, ash and fumes to a height of 20.5 miles, spewing molten rock and pulverized pumice at the rate of 1.5 million tons per second, ultimately releasing a hundred thousand times the thermal energy released by the Hiroshima bombing. The towns of Pompeii and Herculaneum were obliterated by pyroclastic flows. An estimated 16,000 people died from the eruption.
