In 79 A.D., Pompeii was a thriving port city and seaside resort of about 12,000 people in the heart of the Roman Empire (see map, below). The city traded with every corner of the empire. Wealthy Romans had vacation homes there. Pompeii’s streets were busy with citizens, their slaves, and traders from all over.
So on the morning of August 24, few Pompeians were probably paying attention to Mount Vesuvius, about 5 miles away. After all, the volcano hadn’t erupted in more than 1,500 years.
Around midday, however, Vesuvius began smoking, then shooting flames into the sky. Soon it started ejecting molten rock and ash in an enormous cloud that blotted out the sun. Tremors shook the earth.
The writer Pliny the Younger watched from Misenum, across the Bay of Naples. “Ashes were already falling, hotter and thicker,” he later wrote, “followed by bits of pumice [volcanic rock] and blackened stones, charred and cracked by the flames.”
By now, thousands of people were fleeing the city in panic. Those who sought shelter there didn’t have a chance. The rain of pumice gathered deadly force, causing roofs to collapse on everyone below.
Shortly after midnight, Vesuvius exploded again, triggering a surge of ash and hot gas of up to 100 miles per hour. Pompeii and Herculaneum were completely swallowed up.