Pompeii was the symbol of Rome’s moral degeneration. Just like the Prophet Lot’s (pbuh) tribe, the inhabitants of Pompeii, who had also strayed far from religious morality, chose a lifestyle contrary to the morals and life commanded by Allah. And so Allah punished them, just as He punished the Prophet Lot’s (pbuh) tribe. Every society that rebels against Allah inevitably is punished, either in this world or the next, for this is one of Allah’s laws. As Allah reveals:
... You will not find any changing in the pattern of Allah. You will not find any alteration in the pattern of Allah. (Surah Fatir, 43)
Pompeii was destroyed when Mount Vesuvius erupted in 79 CE. Mount Vesuvius is the symbol of Italy, particularly the city of Naples. Dormant now for some 2,000 years, it is also known as the Mountain of Misfortune. Naples stands on the mount's western slopes, and Pompeii stands on its eastern slopes. This disaster struck Pompeii so suddenly that everything seems to have been frozen in time.
There are important lessons to be learned from Pompeii's fate. Historical sources reveal that before its destruction, Pompeii was a hotbed of vice and debauchery and was known for its widespread prostitution. Yet Mount Vesuvius wiped the city from the map in a single moment. Interestingly, despite its terrible eruption, nobody fled. It seems that the people were rooted to the spot, as if unaware of the tragedy. A number of couples have been found, among which are same-sex couples and young boys and girls. Some of the petrified human remains contain perfectly preserved facial features. Their general expression is one of surprise, for Pompeii was destroyed suddenly.
Allah gives an example of the people of a city:
“My Lord, rescue me and my family from what they are doing.” Therefore We rescued him and all his family – except for an old woman who remained behind. Then We utterly destroyed the rest. (Surat ash-Shu'ara', 169-172).
http://www.harunyahya.com/books/faith/abraham_lot/abraham_lot_05.php – part of long article