The Mount Vesuvius eruption on August 24-25, 79 CE, was a tragic, deadly disaster for the residents of Pompeii, a Roman city tucked inland from the Bay of Naples. The volcano destroyed the town and preserved it under layers of ash and rock. Unearthed centuries later, the site serves as a treasure trove of objects and information. Archaeologists and historians can explore the way of life in Pompeii before the destruction.
Pompeii's residents suffered for hours as Mount Vesuvius - like most volcanoes - erupted in several phases. The volcano first trembled and coughed up a cloud that rained pumice stones and hot ash on the city for hours. Eventually, a deadly flow of blisteringly hot volcanic detritus and gas surged down, enveloping the city.
Volcanic eruptions happen in phases - it isn't simply a sudden downpour of lava over the land around the volcano. Though experts have debated which stage of the eruption people were most likely to succumb to, one thing is clear: None of them would have survived the fourth pyroclastic surge, a wall of searing ash and gas that quickly slammed into the city in the early morning of August 25.
When these boiling toxins hit someone, they immediately cause muscle contractions and what one expert called "heat shock" - and this accounts for the crouched, curled positions in which historians discovered so many of the victims. The heat and gas instantly killed anyone it hit, which included everyone who remained in the city. Since they passed in less than a second, there wasn't time for them to feel anything.
Erupting volcanoes emit gases and volcanic chaff high into the air, and Vesuvius was no exception. On August 24, the day of the fateful eruption, a giant cloud - in the shape of what Pliny the Younger described as an "umbrella pine tree" - shot out of the volcano and into the air.
It was so thick, it blotted out the sun - some Pompeians never saw sunlight again. Though it was the middle of the day, the city became cloaked in darkness. Anyone who attempted to flee the city had a difficult time seeing where they were going.
Like many ancient cities, Pompeii stunk even before that fateful August day in 79 CE. But as the volcano was erupting, the air quality worsened due to the thick, toxic gas. Pliny the Younger, witness to the natural disaster, noted how the smell of sulfur in the air intensified before the volcano erupted.
The volcano likely spewed hydrogen sulfide, heralded by a distinct scent reminiscent of "rotten eggs." Between the sulfur and smoke, the smells compelled some Pompeians to repurpose their tunics by tying them around their faces.
Though the earth trembled for days before the eruption, the situation turned deadly on August 24. By evening, the volcano was spewing rocks, some of which measured roughly 3 inches wide. Escaping the storm of stones was risky, but many tried.
Not all were successful: Many Pompeians who took the gamble lost their lives from blows to the head.