Vesuvius had been quiet for centuries - so long that Romans didn't recognize it as a volcano. But the mountain had been restless. A major earthquake in 62 AD had damaged Pompeii severely; repairs were still ongoing seventeen years later. Smaller tremors shook the region in the days before the eruption. Springs and wells dried up. The ground itself seemed uneasy.

On the morning of August 24, Vesuvius erupted with a force that modern volcanologists estimate at 100,000 times that of the Hiroshima bomb. A column of ash and pumice rose 20 miles into the sky. The elder Pliny, commanding the Roman fleet at nearby Misenum, sailed toward the disaster to investigate and rescue survivors. He would die in the attempt, leaving his nephew - Pliny the Younger - to record the only eyewitness account.

The eruption unfolded in phases. First came a rain of pumice stones, accumulating several feet per hour. Buildings began to collapse under the weight. Many residents fled, but others stayed, sheltering indoors, hoping the worst would pass. It didn't.

In the early morning of August 25, the eruption column collapsed, sending pyroclastic surges - superheated gas and ash moving at 450 miles per hour at temperatures of 500 degrees Fahrenheit - rolling down the mountain. These surges killed everyone remaining in their path instantly. The victims didn't suffocate; they died from thermal shock, their soft tissues vaporizing. Within hours, Pompeii was buried. Within decades, its location was forgotten.

Pompeii was rediscovered in 1748 when workers digging a water channel struck ancient walls. Systematic excavation began under the Spanish king of Naples, Charles III. What they found astonished Europe: a complete Roman city, its streets and buildings intact, its frescoes still bright, its mosaics still glittering.

The most haunting discoveries were the voids - spaces in the ash where bodies had decomposed, leaving perfect negatives of the dead. In 1863, archaeologist Giuseppe Fiorelli began filling these voids with plaster, creating casts of the victims in their death poses. A man covering his face. A dog straining at its chain. A mother sheltering her child. The casts made the ancient dead human again.

Pompeii reveals Roman life in extraordinary detail. We know what Pompeiians ate because carbonized food survives - bread still in ovens, olives in jars, fish sauce in amphorae. We know their political opinions because campaign slogans are painted on walls. We know their sexual appetites because erotic frescoes decorated their brothels. We know their private thoughts because graffiti - 'I screwed the barmaid' - still marks the walls.

The city had theaters, temples, an amphitheater, public baths, a forum, restaurants, shops. Its streets are grooved by ancient cart wheels. Its stepping stones still cross the roadways, raised above the runoff that served as sewers. Walking through Pompeii is walking through a Roman city, not a reconstruction but the thing itself.

Four million visitors walk Pompeii's streets each year, making it one of Italy's most visited sites. About two-thirds of the city has been excavated; the rest remains buried, deliberately preserved for future archaeologists with better techniques. New discoveries continue - in 2018, a perfectly preserved 'fast food' shop was uncovered, complete with painted menu and food residue.

Vesuvius still looms over the site, still active, still dangerous. Three million people now live in its potential blast zone. The volcano that created this archaeological treasure could create another disaster. Pompeii reminds us that civilizations end, that the ordinary morning can become the last morning, that time can stop - and leave everything frozen exactly as it was.