Throughout history, people have abandoned entire cities due to war, natural disasters, economic collapse, environmental changes, or disease. For example, Pompeii was buried by a volcanic eruption, while cities like Angkor and Cahokia were deserted probably due to drought and resource depletion. In modern times, cities like Pripyat were evacuated after nuclear disasters. These mass departures often reflect a city's inability to support life under new or extreme conditions.