Approximately 4,000 people perished in the blizzard, where the worst affected areas were buried in up to 8 metres (26 feet) of snow that would have covered a two and half story building.

Beginning at around 1pm on 24 August, Mount Vesuvius sent gas, volcanic ash, and pumice into the stratosphere for up to 20 hours. This was followed by a pyroclastic flow that carried gas and molten rock down from the volcano and which then buried the previously fallen ash.