Natural disasters are major adverse events caused by natural processes like earthquakes, floods, volcanic eruptions, and hurricanes. They often result in loss of life, property damage, and economic losses depending on a population's resilience. Common natural disasters include tsunamis caused by earthquakes under the sea, tornadoes which are violent rotating columns of air, volcanic eruptions which produce lava and ash, earthquakes caused by faults in the earth's crust, and floods from overflowing water. Forest fires, landslides, avalanches, and cyclones are also types of natural disasters, while epidemics can spread disease among human populations on a large scale.