One peaceful August day in A.D. 79, the people of Pompeii were going about their business—baking bread, eating lunch, lounging in the afternoon heat. Suddenly there was a great explosion, and tons of rock, ash, and gas were spewed into the air. Mount Vesuvius was erupting! In just 19 hours, most of the inhabitants were dead, and a layer of ash had buried the city. This is the story of what happened to the advanced city of Pompeii on that fateful day—and how we've learned about its people and culture thousands of years later by digging through the deadly ash.