Tornadoes hit Texas yesterday, destroying a wing of a nursing home, peeling roofs from dozens of homes and sending lorry trailers into the air.
More than a dozen injuries were reported in the Dallas area.
Overturned cars left streets unnavigable and wrecked lorries clogged main roads.
It was estimated that six to 12 tornadoes had touched down in North Texas.
Ten people were injured in suburban Dallas, two of them severely. Three people were injured in Arlington, including two residents of a nursing home who were taken to hospital with minor injuries after swirling winds clipped the building.
Joy Johnston, who was visiting her 79-year-old sister at the Green Oaks Nursing and Rehabilitation Centre, said: "Of course, the windows were flying out, and my sister is paralysed, so I had to get someone to help me get her in a wheelchair to get her out of the room. It was terribly loud."
Dallas-Fort Worth International Airport cancelled hundreds of flights and diverted others heading in.
April is the peak of the tornado season that runs from March until June.
Most of Dallas was spared the full wrath of the storm. Yet in Lancaster, TV helicopters panned over exposed homes without roofs and flattened buildings. Broken sheets of plywood blanketed lawns and covered rooftops.
A pastor at one Lancaster church saw debris swirling in the wind, then herded more than 30 children, some as young as newborns, into a windowless room to ride out the storm. Nearby at the church's school, about 60 more children hid in another windowless room near the women's toilets.
An entire wall of Cedar Valley Christian Academy was taken out in the storm.
Meteorologists said the storms were the result of a slow-moving storm system centred over northern New Mexico.