Entire cities have also been ruined , and some occasionally lost completely , to natural disasters . The ancient city of Pompeii was completely lost during a volcanic eruption in the 1st century AD , its uncovered ruins now preserved as a World Heritage Site . The city of Lisbon was totally destroyed in 1755 by a massive earthquake and tsunami , and the 1906 San Francisco earthquake left the city in almost complete ruin
1906 San Francisco earthquake
1906 San Francisco earthquake
Ruins