On March 18, 1925, one of the deadliest tornado outbreaks in recorded history generated at least 12 significant tornadoes and spanned a large portion of the Midwestern and Southern United States. In all, at least 751 people were killed and more than 2,298 were injured, making the outbreak the deadliest tornado outbreak, March 18 the deadliest tornado day, and 1925 the deadliest tornado year in U.S. history. The outbreak generated several destructive tornadoes in Tennessee, Kentucky, and Indiana on the same day, as well as significant tornadoes in Alabama and Kansas. In addition to confirmed tornadoes, there were undoubtedly others with lesser impacts, the occurrences of which have been lost to history.The outbreak included the Tri-State tornado, the deadliest tornado in United States history and the second-deadliest registered in world history. The 219-mile-long (352 km) track left by the tornado, as it crossed from southeastern Missouri, through southern Illinois, and then into southwestern Indiana, is also the longest ever recorded. Modern meteorological re-analysis has suggested that the extremely long path length and lifespan reported in historical accounts are perhaps more plausibly attributed to multiple independent tornadoes belonging to a tornado family, rather than a single, continuous tornado. Although not officially rated by NOAA, the Tri-State Tornado is recognized by most experts (such as Tom Grazulis and Ted Fujita) as an F5 tornado, the maximum damage rating issued on the Fujita scale.