Fujita scale - Wikipedia
https://en.wikipedia.org/wiki/Fujita_scale
WEBIn total, two tornadoes received the rating of F6, but both were later downgraded to F5. Based on aerial photographs of the damage it caused, Fujita assigned the strongest tornado of the 1974 Super Outbreak, which affected Xenia, Ohio, a preliminary rating of F6 intensity ± 1 scale.
DA: 7 PA: 80 MOZ Rank: 23