On Thursday, March 27, 1890, a major tornado outbreak struck the Middle Mississippi Valley. To this day, this outbreak is still one of the most deadly tornado events in United States history. At least 24 significant tornadoes, several of which were generated by cyclic supercells, were recorded to have spawned from this system, and at least 146 people were killed by tornadoes that day, including a devastating F4 tornado that struck Downtown Louisville, Kentucky, killing at least 76 people and injuring at least 200 others.