What are the causes of natural disasters?
Fires, floods, earthquakes, volcanos.
Sudden changes in the environment can be called natural disasters.
A forest fire ( which can be caused by lightening ) is a natural disaster leaving thousands of acres of forest burned and ten of thousands of animals without homes.
A flood which causes a sudden influx of excess water is an natural disaster eroding land, cutting new channels, and drowning land and animals. One theory is that a catastrophic flood cut the grand canyon. Similar geographic structures were created after the Mt St.Helens eruption that emptied spirit lake. Many structures in Eastern Washington such as the Grand Coule waterfall, the scab lands and the granite erratic boulders in the Willamette Valley were created by the Missoula flood.
An earthquake is a natural disaster. the San Francisco earthquake moved the land 15 to 20 feet in a manner of minuets. causing great damage. There are places where the present ocean shoreline is 1000 feet below the previous ocean shoreline. Major movements of tectonic plates create natural disasters.
Volcanos are a natural disaster. Mount Vesuvius in Italy destroy and buried the cities of Hercalaum and Pompaii