"We could actually hear the train sound for a long time, then for about 30 seconds you hear the snapping and stuff blowing around," said Nelson Austin. He had sprinted to the basement and held the door closed as the storm swept over the house, then emerged to find chaos had come to the Oklahoma City suburb of Moore. "It was pretty intense," he said. "This was like a bombing had happened - people were bleeding and crying, telephone poles were down."
Loretta and Theresa Jones hid in a cupboard, but put their survival down to a higher power. "We were in the closet and calling in the name of Jesus,'' Theresa said. "We heard it coming and - whoa, whoa, Jesus - we called on his name and I felt his arms come around us and save us from that tornado. And I thank God for that."
For all the science that now surrounds the forecasting and explanation of tornadoes, a well-built cupboard and a strong faith are probably still about as useful as anything else in surviving a tornado as strong as that which devastated Oklahoma on Monday night.
The Doppler radars of the local television stations showed only too clearly the trouble brewing in the skies as evening fell: the tell-tale hooked shapes of the thunderstorms, the vast twisters forming up and sweeping across the towns, farms and highways. In most houses, hurricane warnings would have sounded: the hurricane sirens linked to the government system, or the weather channel radios which switch on automatically. For some, escape to a cellar or shelter may have saved their lives; but for many, it was either too late, or they had not heard the alarms in the first place.
Oklahoma is only too used to the hellish roar of the tornado. It sits square in the middle of "Tornado Alley", a belt of land that stretches down the centre of the country where the conditions for tornado formation are particularly propitious. Here, in the lowland areas of the Ohio, Mississippi and Missouri valleys, the twister is a constant threat to life and property. Oklahoma has an average of 52 tornadoes a year and over 200 people have been killed in tornadoes in the state since 1950. The Red River Valley Tornadoes of April 1979, almost exactly 20 years ago, claimed 56 lives in the south of the state and in northern Texas.
But few of the hurricanes have been of this intensity. There have only been 50 F-5 - or "incredible" - tornadoes since 1950, according to government statistics, and even fewer F-6s, officially designated as "inconceivable". Of the 1,254 tornadoes in the US last year, 33 resulted in deaths - a total of 129, the highest number since 1974, when a "super outbreak" of 148 tornadoes in 24 hours killed over 300 people.
Unsurprisingly, one of the centres where hurricanes are studied most intently in the world is in Norman, Oklahoma, the home of the National Severe Storms Laboratory. Scientists there said that the storms may have been a mile wide at times. "I watched from my house when the tornado crossed Oklahoma City. It was a monster, it was huge," said Dave Imy, a meteorologist at the National Weather Service's Storm Prediction Centre, clearly in awe of what he had seen and heard.
Although scientists know in some detail how and why tornadoes form, there is much that they do not know about why sometimes apparently similar conditions produce different sizes of tornado. And timing is still the crucial factor: storms form very quickly, and tornadoes form out of them in minutes. That often leaves little time to alert residents. The spread of weather radios and tornado sirens has helped, as has the ability of television to inform people when a storm is imminent. But all too often, there is just not enough time.
For now, the authorities will concentrate all their efforts on recovery. Clearing up after a tornado is always a vast task, exacerbated by the fact that roads are often blocked, telephone lines down and airports closed. There were widespread electricity cuts in Oklahoma. At least six sub-stations were out and power lines were down across the state.
The state was also in desperate need of assistance with casualties. Hundreds were wounded, some of them seriously. Medical facilities were struggling to keep up, with patients being treated in corridors and hospital cafeterias. The Oklahoma Blood Institute was open all night to take donations, but the state was running out of blood. Many of the worst injuries were caused by flying glass and wreckage.
For many people, it will take years to recover from the loss of everything they owned. In Moore, one of the suburbs worst hit, Jennifer Schantz stood in what had been her front garden, with nothing but rubble around her, clutching her young daughter. "We just bought this house,'' she said.