A disaster is defined as a sudden event that causes widespread human and material losses exceeding a community's ability to cope. Disasters can be natural, caused by earthquakes, volcanic eruptions, cyclones, floods, droughts or tornadoes. They can also be man-made, such as chemical spills, nuclear accidents, acts of terrorism, or other industrial and transportation incidents. Preparing for disasters includes activities like detection, incident command, safety, assessment, support, triage, evacuation and recovery. Both natural and man-made disasters have severe negative effects including loss of life and property as well as long-term environmental and health impacts.