It's one of the nation's most infamous tornado outbreaks, but it also spurred sorely needed improvements in both severe weather forecasting and safety.

At the time it was the largest tornado outbreak in U.S. history and produced the longest tracked tornado in Indiana on record Of the seven top/major tornado outbreaks on record in the U.S., the

After hail, heavy rains and more than 30 tornadoes drenched the region, officials warned that a “generational flooding” disaster was possible.