A tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cloud. Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel whose narrow end touches the earth and is often encircled by a cloud of debris and dust.

Most Deadliest Tornado

March 18, 1925

The most extreme tornado in recorded history was the Tri-State Tornado, which roared through parts of Missouri, Illinois, and Indiana on March 18, 1925. It was likely an F5, though tornadoes were not ranked on any scale in that era. It holds records for longest path length at 352 km 219 mi, longest duration at about 3.5 hours, and fastest forward speed for a significant tornado at 117 km/h 73 mph anywhere on Earth. In addition, it is the deadliest single tornado in United States history 695 dead.
Massive Tornado Caught on Tape | April 27, 2011