An earthquake is the shaking of the Earth's surface caused by a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes can range from minor tremors to violent shakes that toss people and destroy cities. The risks of earthquakes include injury, death, and destroyed properties. It is important to be prepared by having a safety-first mentality, being aware of one's surroundings as houses, trees and posts can be dangerous during a quake, and having an emergency kit with tools, equipment, medicines and supplies.