18 Major Hazards Hazards are natural or manmade conditions with the potential to cause death, injury or extensive property damage. The District of Columbia is vulnerable to a variety of hazards, both natural and manmade. In 1995, the city conducted a hazard analysis that identified 14 major hazards based on historical data, frequency of occurrence, damage statistics and the city's overall vulnerability. Since that initial assessment the list of hazards has been revised and updated several times. Currently, there are 18 major hazards affecting the District of Columbia, including:      Thunderstorms Winter Storms Snow  Transportation Accidents Special Events, Demonstrations and Civil Disruptions Urban Floods Flood Factsheet* Flood Factsheet: Proper Use of Sandbags* Flood Factsheet: Protection of HVAC Equipment* Utility Failures Electricity Shortages Hurricanes Hurricane Factsheet* Radiological and Hazardous Materials Urban Fires  Terrorism Extreme Weather Heat Cold Explosions (Manhole Covers) Critical Resource Shortages Human Viruses and Epidemics  Earthquakes Tornadoes Prison Problems Urban Crime