The death toll has risen to 41 in disaster caused by storms and floods in southern and central states of the United States.
Many buildings have flattened and transport has been badly affected.
At least 11 people were killed in the Dallas area over the weekend by tornadoes, including one packing winds of up to 322 km per hour. The twister hit the city of Garland, killing eight people and blowing vehicles off highways.
National Weather Service Meteorologist Matt Bishop said that a tornado of that strength is very rare in a metropolitan area.
According to official, three people died in the Dallas metropolitan area and many others were reported injured in the region.
In Illinois and Missouri, flash flooding has killed at least 11 people.
The storms came on the heels of tornadoes that hit two days before Christmas, killing at least 18 people in Mississippi.
The weather service issued severe weather advisories for large parts of the central United States, including a blizzard warning for parts of New Mexico, Texas, Oklahoma and Kansas and a flash flood watch stretching from Texas to Indiana.
Nearly 1,300 flights were cancelled because of the bad weather conditions on Sunday.
