Palm Sunday tornado outbreak occurred on March 28, 1920. Thirty-eight significant tornadoes hit the Midwest and Deep South states. The outbreak left over 380+ dead, 1,215 injured. Many communities and farmers alike, were caught off-guard, as the storms moved to the northeast at speeds that reached 100 km/h (62 mph). Most of the fatalities occurred in Georgia (201+), Indiana (56), and Ohio (55), while the other states had lesser amounts.

Severe thunderstorms began developing in Missouri during the early morning hours. The storms moved quickly to the northeast towards Chicago, Illinois. The first tornado injured five people 56 km (35 mi.) southeast of Springfield, Missouri in the pre-dawn hours in Douglas County. This first twister was a harbinger of things to come, as the morning went on and the atmosphere began to destabilize, due to the abundance of sunshine that preceded the cold front in the dry slot area, which covered the lower Great Lakes region, extending southward well past the Ohio River Valley.

http://en.wikipedia.org/wiki/Palm_Sunday_tornado_outbreak_of_1920