ABSTRACT
Mass disasters usually occur suddenly and cause loss of human life, ecological damage , and a deterioration of health and supporting health services, as well as loss of essential infrastructure. There are natural disasters such as flood, hurricane, or earthquake, and there are manmade disasters, intentional acts of terrorism, and unintentional disasters such as airplane disasters or major building and ship fires. Each of these may take place in a single location (Valujet plane crash) or in multiple locations (Hurricane Katrina) and may occur within a limited time or extended time periods (ethnic conflicts). Acts of terrorism are particularly disastrous because they encompass all three elements. They may take place in one or more sites at once , over a short or extended period of time, and they are intentional and therefore subject to repetition.
