Here in Oklahoma we have lots of tornados!!! But because of thick clay soils, very few basements in homes. So many people have underground tornado shelters. The old fashioned ones like my grandparents had are underground dirt cellars with timber supports, also used as food storage root cellars. Today, they can be concrete type boxes buried in the back yard with metal doors, or underground inside the garage. Ours is a large steel box, 4' wide, 8' long and 5'tall, with a sliding door/roof, set in ground in the garage. We store water, emergency food and a medical kit in it, along with battery operated lanterns.
Nowadays with the advanced weather radars, we usually have warnings on TV about dangerous weather conditions a day or several hours in advance--called a tornado watch. Most people also have weather warning radios in our homes that go off with loud buzzers when the local area is under a tornado warning. Finally, the local communities have the public weather sirens that go off when a tornado has been verified on land. But we all watch the tv for the weather conditions, and if it looks likely, we pack critical items, take the dog and get inside the underground shelter before the sirens go off! As long as we still have electricity and wifi, we take the iPad in the shelter and a radio so we know what is going on while we are down there. The winds and rains are usually quite loud in storms like these, so we stay in the shelter till it passes or we can hear all clear announcements on the radio/ipad.
It sounds scary, and it is, but just something we are used to doing.