Vesuvius killed the 2,000 people of Pompeii quickly—in about 15 minutes, new research shows. They died not when lava reached them after the volcano erupted, but in a cloud of ash and gases, the Guardian reports; the victims had no escape and were unable to breathe. Most of them died at home, many in their beds. "Those 15 minutes inside that infernal cloud must have been interminable," researcher Roberto Isaia says. "The inhabitants could not have imagined what was happening. The Pompeiians lived with earthquakes, but not with eruptions, so they were taken by surprise and swept away by that incandescent cloud of ash." The study of the 79 AD eruption was conducted by a team from Italy's University of Bari working with the British Geological Survey.
The cloud contained "CO2, chlorides, particles of incandescent ash, and volcanic glass," Isaia says, and it was more than 100 degrees. It would have taken only a few minutes for the pyroclastic flow to reach the Roman city, he says. The flow would then have covered the bodies. The study's goal was to understand the flow's effect on Pompeii and its people, as well as how long it lasted, per the Guardian. "It is very important to be able to reconstruct what happened during Vesuvius's past eruptions," researcher Pierfrancesco Dellino says, "starting from the geological record, in order to trace the characteristics of the pyroclastic currents and the impact on population." About a million people visit Pompeii every year. (A ceremonial chariot was found intact last month at the site.)