A tornado is a violent, rotating column of air which is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. Tornadoes come in many sizes but 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. Tornados were in the all continent without Antarcida. They perform the most in the USA. Last time were in New Orlean and it name was Gustav. It killed many people. The biggest and the most dangerous was Tri-State Tornado in 18th march 1925. It killed about tousand people.
When tornado is coming, people save their houses and hide in cellar. They take children with them and wait in the end of tornado. They always take food, warm clothes and drink for a long time, because they never know how long they have to stay in the shelter. When tornado go out, it make a lot of distroying. The houses are distroyed the same like nearest shops, parks, trees, schools and different buildings. People from different countries collect money for help victim. They organise collecting in schools and in works.
You can imagine that we can't do anything but it isn't true.