Pompeii

Pompeii is a city in Italy. A group of Pyrovile landed in the region and slept for millions of years untill awakened by an earthquake in 62 AD. At this point they set in motion a plan to terraform the earth into a planet of fire, so it could become their new world.

In 79 AD, the doctor arived, and foiled their plan. Unfortunatly, while this saved the Earth, it also trigured a catastrophic erruption of the Volcano known as Mount Vesuvius. The eruption completely destroyed the city and killed most of it's population, 20,000 people. The erruption was so powerfull that it briefly created a time rift, which by echoing back in time granted a number of citizens precognitive powers.

This event was according to the doctor a crucial and unchangable event in history. Jack Harkness in his rougue days also claimed it was an excelent setting for a con job.

Eventully the city was rediscovered and Humanity remembered it's faith. (DW: The Fires of Pompeii)