What were the deadliest U.S tornadoes?

The "Tri-state" tornado of 18 March 1925 killed 695 people as it raced along at 60-73 mph in a 219 mile long track across parts of Missouri, Illinois and Indiana, producing F5 damage. The death toll is an estimate based on the work of Grazulis (1993); older references have different counts. This event also holds the known record for most tornado fatalities in a single city or town: at least 234 at Murphysboro IL. The 25 deadliest tornadoes on record are listed here. We also have web links related to this and other major tornado events. What were the deadliest U.S tornadoes days ? On 3 April 1974, the main day of the two-day "Super Outbreak," tornadoes killed 308 people. The next deadliest day for tornadoes was 11 April 1965, the original "Palm Sunday Outbreak," where 260 perished. A list is online of top 20 deadliest tornado days since detailed record keeping began in 1950. What was the biggest out break of tornadoes? 147 tornadoes touched down in 13 U.S. states on 3 and 4 April, ...  more