<P> This article lists various tornado records . The most "extreme" tornado in recorded history was the Tri-State Tornado, which spread through parts of Missouri, Illinois, and Indiana on March 18, 1925 . It is considered an F5, though tornadoes were not ranked on any scale in that era . It holds records for longest path length at 219 miles (352 km), longest duration at about 31⁄2 hours, and fastest forward speed for a significant tornado at 73 mph (117 km / h) anywhere on Earth . In addition, it is the deadliest single tornado in United States history with 695 fatalities . It was also the third - costliest tornado in history at the time, but has been surpassed by several others non-normalized . When costs are normalized for wealth and inflation, it still ranks third today . </P> <P> The deadliest tornado in world history was the Daulatpur--Saturia tornado in Bangladesh on April 26, 1989, which killed approximately 1,300 people . In its history Bangladesh has had at least 19 tornadoes kill more than 100 people, almost half of the total for the rest of the world . </P>

What was the deadliest tornado in the united states