UNESCO Dossier on Education in Emergency, Crisis and Reconstruction:
"Armed conflicts, natural disasters (such as earthquakes, floods and cyclones), ecological and man-made disasters (desertification, drought, deforestation, and so forth) and deterioration of living conditions (poverty, unemployment, famine, and other afflictions) results in large scale fatalities and injuries to the population. It often creates massive displacement and migration of population and devastating physical destruction.
Since 1945 we have seen 150 conflicts erupt throughout the five continents, resulting in 20 million deaths and 60 million casualties."
This page may be of use to U.S. Educators in the wake of Katrina.