Tornadoes are devastating atmospheric events that affect the ecology and lives of people in their path. Tornadoes are defined as "a violently rotating column of air, in contact with the ground, either hanging from or beneath a cumuliform cloud, and often (but not always) visible as a funnel cloud" (Glossary of meteorology, 2011). . The Tri-State tornado was the deadliest tornado in the United States. It remained on the ground for a total of 219 miles across areas of Missouri, Illinois and Indiana, killed a total of 695 people and caused an estimated $16.5 million in damage (National Weather Service, 2011). Fortunately, the tornado's path was largely rural farmland with small towns scattered among them.Figure 1. Tornado's path across the three states. The beginnings of one such storm began around 1 p.m. northwest of Ellington, Missouri, on March 18, 1925. It moved northeast toward the towns of Annapolis and Leadanna before making landfall two schools. Before the tornado even reached Illinois, it caused 11 deaths (National Weather Service, 2011). The tornado then passed through Gorham, a completely demolished town, and continued on its way recording the fastest speed at 73 mph. Murphysboro was one of, if not the most devastated towns along the way. The tornado killed 234 people, the most for a single community (National Weather Service, 2011). The total death toll in Illinois was at least 613 people. The next town, Griffin, Indiana, was completely demolished. The last town to be hit by the tornado was Princeton. About 10 miles northeast of Princeton was the location where the tornado retreated into the clouds (National Weather Service, 2011). Although there is no...... middle of paper ...... received March 3, 2011 from United States Immigration Services: http://www.geographic.org/climate/ c.htmlNational Weather Service. (March 3, 2011). Tri-State Tornado Website. Retrieved March 3, 2011 from NOAA: http://www.crh.noaa.gov/pah/?n=1925torNOAA. (March 3, 2011). Improved Fujita scale. Retrieved March 3, 2011 from NOAA: http://www.spc.noaa.gov/efscale/NOAA. (December 14, 2007). History of tornado forecasting. Retrieved March 4, 2011 from NOAA: http://celebrating200years.noaa.gov/magazine/tornado_forecasting/welcome.html#knowledgeUSA Today. (2005, December 28). The 1925 tri-state tornado was the worst in U.S. history. Retrieved March 3, 2011 from USA Today: http://www.usatoday.com/weather/tri-state-tornado.htmUSA Today. (2000, May 4). Tornado Chase 2000. Retrieved March 3, 2011 from USA Today: http://www.usatoday.com/weather/tornado/2000/chase/chat/wclimoqna.htm