Violent natural disasters have been a fact of human life since the beginning of the species, but the death counts of the most ancient of these disasters are lost to history.
E.g. The Mediterranean island of Stroggli, is believed to have been completely wiped out by a volcanic eruption and ensuing tsunami that eradicated the entire Minoan civilization around 1500 B.C. How many lives were lost? We’ll never know.
A natural hazard is a threat of a naturally occurring event that will have a negative effect on humans. A natural hazard becomes a natural disaster when it takes place, causing significant loss of life and property.
Check out the list of 10 worst disasters in human history: https://www.vikingsteelstructures.com/carports-infographics/10-worlds-worst-disaster-in-human-history
