Yeah, natural disaster was in the Med. Sea. Earth Quake. tidal wave. Villages near the shore were wiped out. St. Louis. Huge flood wiped out the 40,000 people. Drought or flood. Or poor sanitation with lots of bad germs will depopulate a city. A side note: 700 BC the Nubians of Africa had tetracycline naturally occurring in the soil. They made beer with the antibiotic and had good health.
Easter Island: they were busy chopping down the big trees to build huge outrigger canoes for deep sea fishing. Yes good for the economy. They forgot to plant new trees. They chopped down trees to use as rollers to move the big huge stone slabs. Then they eventually chopped down all of the big trees. After their fleet of deep sea canoes was obsolete from old age, they had no more trees to convert into new canoes. The economy fell apart and degenerated into gang warfare and chaos. And all of that happened before Captain Cook arrived.