Forecasters say tornadoes could hit Monday in parts of Arkansas, Kansas, Missouri and Oklahoma - roughly the same area hit Sunday night.
Oklahoma has been the hardest hit, with two people killed near Shawnee and at least 39 others injured throughout the state.
One mobile home park resident in Shawnee says he emerged from a storm cellar with his wife and children to find that "everything is gone."
An Oklahoma sheriff is crediting early warnings for a low death toll during the tornado outbreak.
Authorities say a 79-year-old man died Sunday when a twister flattened much of a mobile home park southeast of Oklahoma City.
Sheriff Mike Booth credited TV and radio stations that provided wall-to-wall broadcasts of the violent weather.
This segment aired on May 20, 2013.