A tornado is a violently spinning column of air that can start to form during a thunder storm, there are about 45,000 a day worldwide. Of course, not all thunderstorms bring about tornadoes and not all tornadoes bring about total destruction. The most destructive ones occur in lndia, Bangladesh, and "Tornado Alley" in the USA. The worst ever "twister" hit this area in March 1925, when a huge tornado travelled across Missouri, lllinois and Indiana, killing 695 people and injuring a further 2,027