The tornadoes that cause the most severe damage are rated EF5 on the Enhanced Fujita scale
The F5 (or EF5 as of February 2007) tornado is the most damaging category.
The most damaging tornado on record struck Joplin, Missouri on May 22, 2011. The cost of damage was $ 2.8 billion.
That depends on the tornado. In a single vortex tornado the most damaging part would be the edge of the tornado's core, analogous to the eye wall of a hurricane. In a multiple vortex tornado, the most damaging part would be the subvotices that orbit within the main circulation of the tornado.
Tornadoes are not given names as hurricanes are. The most damaging tornado recorded so far was the Topeka, Kansas tornado of 1966.
An F5 Tornado is the most powerful category of tornado possible. This tornado pulls well-built homes off their foundations and into the air before shredding them and wiping the foundation clean.
A tornado classified as EF-5 on the Enhanced Fujita Scale causes the most damage. These tornadoes have wind speeds of over 200 mph and are capable of destroying well-built homes and leveling entire neighborhoods.
An F4 or higher tornado (the only higher rating being F5) is classified as violent.
To be classified as a tornado, a funnel cloud must make contact with the ground. Once the funnel cloud touches the ground, it becomes a tornado and is classified based on its size, intensity, and associated damage.
April 21st 1967 Lake Zurich had a F4 tornado.
The largest tornado even recorded caused about $160 million dollars in damage, but keep in mind this wasn't the most damaging tornado or the strongest. The tornado with the strongest recorded winds caused $1 billion in damage (about $1.3 billion in today's dollars). The most damaging tornado recorded caused the equivalent of $1.7 billion in today's dollars.
The most destructive single tornado on record was the Joplin, Missouri tornado of May 22, 2011 which causes $2.8 billion in damage. The most destructive level of tornado is an EF5 on the Enhanced Fujita scale (the Joplin tornado was an EF5). Such tornadoes wipe well-built houses clean off their foundations.
The Tri-State Tornado of 1925 is considered the deadliest tornado in U.S. history, causing significant damage in Missouri, Illinois, and Indiana. It traveled over 200 miles, reaching estimated winds of 300 mph and causing 695 fatalities and over 2,000 injuries.