Damage during a Tornado

Personally:
Imagine living without electricity, water, clothing or food. Imagine losing everything in a matter of minutes and not knowing where to go or what to do.Hundreds of people who lived in Grand Island on June 3, 1980, don't have to imagine. They know, and they remember.

Economically:
Twisters can cause thousands to millions of dollars in damage.  The Oklahoma City tornado on May 3, 1999, was one of the most expensive tornadoes in U.S. history.  It resulted in one billion dollars of damage including destroying over 2,500 structures.  Tornadoes are natural disasters that can devastate cities and leave many people without a home.

What kind of damage is caused by tornadoes?
What kind of assistance is available for states that have been hit by tornadoes?

Natural Disasters
Fujita Scale