An introduction to tornadoes including how tornadoes happen and how to survive a tornado.

Includes index.

What happens when a tornado hits? -- Where do tornadoes occur? -- How are tornadoes formed? -- How do we measure tornadoes? -- How are people warned? -- Who are storm chasers? -- Where is Tornado Alley? -- Where was the world's worst tornado? -- Can tornadoes happen at sea? -- Are tornadoes getting worse? -- What's the best kind of house to live in? -- How would you survive in a tornado? -- Tornado facts -- Glossary -- What do you know about tornadoes?