Together, these and other emergencies imperil the health of hundreds of millions of people and substantially increase levels of morbidity and mortality. A natural disaster is a major adverse event resulting from natural processes of the earth. Common examples of these disasters are train accidents, aero plane crashes, collapse of buildings, bridges, mines, tunnels, etc. The earthquake that ravaged haiti in january 2010, killed over 200,000 people and the country still hasn't fully recovered. As a consequence of human effects, some natural disasters have grown.