Tornado shelters are a common feature of homes in Tornado Alley. Many homes have had them dug into the ground since the 1800s:
Tornado Shelter Images
This woman is pointing to the shelter that undoubtedly saved her family's life from the Moore, Oklahoma tornado. Look at her neighborhood. The streets were lined with houses.
The deadly Moore tornado was beyond devastating. Much of the nation listened in on the radio during its long course across Oklahoma.
Enhanced Fujita scale:
EF0 65–85 mph Light damage
EF1 86–110 mph Moderate damage
EF2 111–135 mph Considerable damage
EF3 136–165 mph Severe damage
EF4 166–200 mph Devastating damage
EF5 200 mph Incredible damage
100 miles per hour (MPH) = 161 kilometers per hour
This video begins with two people watching the tornado develop while listening to the National Weather Service radio traffic describing what is happening. It is not easy to follow the radio conversation. This portion finishes around 14:50. Later it contains an assemblage of synchronized video following the tornado over the course of its life.
People without a dedicated shelter run to the smallest, heaviest-walled room in their basement, or on the ground floor if no basement. Without a basement, run to the bathroom and shelter in the bathtub. If you have time bring a mattress or heavy piece of furniture with you to cover yourself with it.
If caught outdoors, get on your face in the lowest ground you can find. A ditch works well. Wind speed is zero at ground level and rapidly increases. The majority of tornado deaths and injuries are from being struck by objects hurtling through the air, or falling on people in buildings.
Do not abandon your car and run up under a bridge overpass. This location is far more dangerous than face down in a ditch. Here is proof:
Highway Overpasses as Tornado Shelters: Fallout From the 3 May 1999 Oklahoma/Kansas Violent Tornado Outbreak
Note in slide 7 the silhouettes of people who took shelter under the overpass but were scoured away by flying dirt and gravel.
Key points for surviving:
Have a plan in advance.
Tornado paths are unpredictable. Don't rely on outrunning them. Most do move southwest to northeast, but they often make deviations.
Near the funnel rain is so heavy the funnel is usually not visible. Take shelter as soon as you hear the sirens.
Do not drive away to escape. Roads may be packed with other drivers. Many people killed in their cars left homes with no or slight damage.
If caught outside, get on the ground in the lowest place you can reach.
Get in the shelter. If you don't have one, get into the strongest interior room of your house. Cover yourself with a mattress or table if you can.