A natural disaster is effect of a a natural hazard. Example: flood, tornado, hurricane, volcanic eruption, earthquake, heatwave, or landslide.
t leads to financial, environmental or human losses. The resulting loss depends on the vulnerability of the affected population to resist the hazard, also called their resilience. This understanding is concentrated in the formulation: "disasters occur when hazards meet vulnerability.
The five most mortal natural disasters between 1750 and 1931
One: Earthquake, Lisboa in 1755.
Two: Hurricane, San Calixto in 1780.
Three: Volcanic eruption, Indonesia in 1815.
Four: Earthquake, Tokyo in 1923.
Five: Flood, China in 1931.
In my opinion, a natural disaster can't be prevented. They not are the result of human interaction. Is natural, and nobody know what can happened.