48 Hours Explore how and where tornadoes are formed and the destructive power of these deadly twisters. Discover how Earth is battered from the sky by hurricanes, tornadoes and cyclones as volcanoes and earthquakes rumble from below.
Natural disasters are just that - natural.
But their destruction has a profound impact on humans and where they live. In 1999, tornadoes killed 94 people in the United States, according to the National Oceanic and Atmospheric Administration. Every year, hundreds of tornadoes touch down in this country. CBS News ' 48 Hours takes a close-up look at this powerful and often terrifying force. Correspondent Peter Van Sant reports on the killer tornado that struck Oklahoma in 1999.