On the morning of August 24, 79 CE, a foreboding plume of smoke emerged from Mount Vesuvius; citizens of Pompeii and Herculaneum looked on and prepared themselves for incoming destruction. Some left immediately when the volcano began showing signs of a potential eruption, others packed their belongings and attempted to leave hours later, while a few thought they could wait out the blast.
Though over 15,000 people lost their lives and became preserved bodies in Pompeii, others managed to survive by taking heed of early warning signs and escaping to a safe area before volcanic activity became too dangerous.
Be Wary Of Earthquakes
The area around Pompeii was prone to earthquakes and contemporaries even noted damaging seismic activity in 62 CE:
Pompeii, so they tell me, has collapsed in an earthquake. It is a well-known city in Campania, with Surrentum and Stabiae on one side and Herculaneum on the other. The coastline here pulls back from the open sea and shelters Pompeii in a pleasant bay. Some areas near Pompeii were shaken as well. The earthquake occurred during the winter, though it had always been said that the winter was not the dangerous time of year. But it was on the fifth of February in 62...
Earthquakes and volcanic activity are related. If you're in a region with a noticeably active volcano, take heed of any seismic disturbances. Though earthquakes do not always precede a potential eruption, they're often a sign of volcanic activity.
Vesuvius and Pompeii are in a seismically active region. They lie along the Campanian volcanic arc, a subduction zone where one tectonic plate goes under another. Whenever the tectonic plates move, they cause an earthquake; however, earthquakes can also be caused by rapidly moving magma under the Earth's crust. Regardless of the cause, the earthquake should have acted as a warning.
Some of the Roman elite avoided Pompeii after the earthquake for fear of another event, but generally, residents rebuilt and continued to enjoy the region's prosperity.
If You See Smoke Emanating From Vesuvius, Go The Other Direction
According to Pliny the Younger, the eruption of Mount Vesuvius in 79 AD lasted for over a day. At the first sight of smoke, his uncle Pliny the Elder, a commander of a Roman fleet in the Bay of Naples, eased the panic among his colleagues and remained unconcerned. But as time passed, Pliny the Elder became more concerned about the large cloud rising above Pompeii and went to investigate:
About one in the afternoon, my mother desired him to observe a cloud which appeared of a very unusual size and shape. He had just taken a turn in the sun and, after bathing himself in cold water, and making a light luncheon, gone back to his books: he immediately arose and went out upon a rising ground from whence he might get a better sight of this very uncommon appearance. A cloud, from which mountain was uncertain, at this distance was ascending... He ordered the galleys to be put to sea, and went himself on board with an intention of assisting... several other towns which lay thickly strewn along that beautiful coast.
Though his actions were courageous, it was a decidedly bad decision for his own survival. According to his nephew, Pliny the Elder was later overwhelmed by smoke and suffocated amid "gross and noxious vapour."
Evacuate Immediately After The Volcano Shows Signs Of Possible Eruption
Pliny the Younger, who was at nearby Misenum, recalled the land shaking as the sky became increasingly dark. As it became increasingly clear that he and his aunt were unsafe, they decided to leave. As they left their house, they saw panic-stricken people running about, trying to find their loved ones. According to Pliny, ash fell all around them and they heard "shrieks of women, the screams of children, and shouts of men..."
Pliny and his aunt later left Misenum, but they were lucky. Those who left within the first few hours did not have to deal with many of the volcano's most destructive forces. Though ash and pumice fell from the sky from the beginning of the eruption, the rocks initially were not large enough to slay a person and the ash was relatively light. The first pyroclastic flow, which was the most dangerous part, didn't hit Pompeii until almost a whole day after the volcano erupted.
Many decided to stay, including Pliny the Elder, who thought the best action would be to take cover and wait out the eruption. He, like others who remained, succumbed to Vesuvius.
Have An Escape Route In Case Of An Emergency
Pompeii had an elaborate network of streets dating back to the 4th century BCE; however, an archaeological study of the roadways determined the city was heavily congested with traffic. Two-way roads serviced the city gates and fortifications, but narrow one-way roads branched off from those two-way streets.
The streets were not terribly vehicle-friendly; 84% of the named streets were one-way and it was a challenge for any ox- or horse-drawn cart to navigate the city. If a cart made a wrong turn onto a one-way street, it would have been difficult to turn the cart around and relieve traffic.
This would have been a large problem in a situation like the 79 CE eruption. Though there were streets which exited the city, if you did not have a route that addressed the city's congestion, it may have been difficult to leave.