Bill Waugh / Reuters
Leah Hill, of Shawnee, Okla., is hugged by a friend as they look through Hill's scattered belongings from her home which was destroyed by a tornado, west of Shawnee, on May 19.
A vast area of the central U.S. was warned to prepare for storms on Monday, after tornadoes killed one and injured 21 in Oklahoma and also hit Iowa and Kansas.
“After over 300 reports of severe weather on Sunday, another round of dangerous severe weather is expected Monday with the greatest threat once again in the southern Plains targeting Oklahoma and parts of Kansas, Missouri and Arkansas,” the National Weather Service said. “However, severe weather is possible much further north towards Chicago and Madison as well."
The weather service issued maps showing the risk of severe storms and tornadoes.
A trailer park near Oklahoma City was turned into “splinters and rubble,” weather.com reported, as multiple twisters sent people running for cover along a 100-mile corridor.
James Hoke, who lives with his wife and two children in the Steelman Estates Mobile Home Park in Shawnee, Okla., told the Associated Press that they went into their storm cellar as the storm approached. When they came out, their mobile home had vanished. "It took a dead hit," Hoke said.
Shalyn Phillips / TVNweather.com
A tornado is captured on camera near Viola, Kansas, on Sunday.
"You can see where there's absolutely nothing, then there are places where you have mobile home frames on top of each other, debris piled up," Pottawatomie County Sheriff Mike Booth told the AP. "It looks like there's been heavy equipment in there on a demolition tour.
"It's pretty bad. It's pretty much wiped out," he added.
Elsewhere In Oklahoma, tornadoes were also reported at Edmond, Arcadia and near Wellston to the north and northeast of Oklahoma City, weather.com said.
Don Lynch, of Pottawaomie County Sheriff’s Office, said a 79-year-old man had been killed.
Twenty-one people across the state were injured, according to Keli Cain, an Oklahoma Department of Emergency Management spokeswoman.
The Norman, Oklahoma, office posted a Twitter alert warning of a tornado about to strike Pink, a town not far from Shawnee, at around 6:15 p.m. local time (7:15 p.m. ET).
Trucks near Shawnee, Oklahoma, are tipped over and homes are damaged after a tornado touched down late Sunday.
"Large tornado west of Pink!" the post read. "Take cover RIGHT NOW in Pink! DO NOT WAIT!"
"You could be killed if not underground or in a tornado shelter," it added. "Complete destruction of neighborhoods, businesses and vehicles will occur. Flying debris will be deadly to people and animals."
Randy Grau told weather.com of the moment he realized it was time to take cover in his Edmond home. He said he looked out a window as the weather worsened and believed he saw a flock of birds heading down the street.
"Then I realized it was swirling debris. That's when we shut the door of the safe room," said Grau, adding that he, his wife and two children remained in the room for 10 minutes.
The storm prompted an unusually blunt warning from the central region of the National Weather Service, which covers 14 states.
Authorities are telling people from Iowa to Oklahoma to prepare for powerful storms. NBC's Janet Shamlian reports.
Oklahoma’s Governor Mary Fallin on Sunday declared a State of Emergency for 16 Oklahoma counties because of tornadoes, severe storms, straight-line winds and flooding.
"Our hearts and prayers are with those Oklahomans who have been affected by today's severe weather," Fallin said in a statement.
Carla Tollett, an information officer for St. Anthony Shawnee Hospital, said it was treating one patient who was in a critical condition and had also seen 10 other less seriously injured people.
Various power companies reported more than 57,000 outages related to the storms.
KFOR in Oklahoma reports that there is damage after an apparent tornado hit the ground near Shawnee, Oklahoma on Sunday.
In Wichita, Kansas, a tornado touched down near Mid-Continent Airport shortly before 4 p.m., weather.com reported. Thousands of homes and businesses lost power, but the twister missed the most populated areas of the city.
Sedgwick County Emergency Management Director Randy Duncan told weather.com there were no reports of fatalities or injuries in Kansas.
In Iowa, two tornadoes were reported touching down on Sunday night -- one near Huxley, about 20 miles north of Des Moines, and one in Grundy County, northeast of Des Moines.
The Associated Press and Reuters contributed to this report.