May 20, 2013 -- At least one person died after a series of tornadoes ripped across the Midwest Sunday, injuring dozens while leaving a path of devastation in a region that is expected to see more severe weather later today.
A 79-year-old man died near a mobile home park in Shawnee, Okla., which was reduced to rubble after one of many Midwest twisters ripped through the area, according to Pottawatomie County Sheriff Mike Booth. At least 21 others in Oklahoma were taken to local hospitals to be treated for injuries.
The Shawnee tornado was one of several that touched down in the nation's midsection Sunday. Twisters, hail and high winds also struck Iowa and Kansas as part of a devastating, northeastward-moving storm system that stretched from Texas to Minnesota. Kansas, Illinois, Iowa, Missouri, Nebraska and Oklahoma were ravaged by 50 tornadoes this weekend.
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The National Weather Service says that one of the tornadoes near Wichita, Kan., registered EF-1 winds up to 110 mph. It was on the ground for an estimated 4.5 miles.
Forecasters say tornadoes could hit today in roughly the same area as Sunday night, affecting millions of people. Large cities like St. Louis, Chicago, Kansas City, Minneapolis, Detroit, Green Bay, and Milwaukee could see damaging hail and a chance for isolated tornadoes. Areas just north of Dallas, Oklahoma City, Tulsa and Springfield, Mo., are at a moderate risk for tornadoes.
The mobile home park in Shawnee, 35 miles south of Oklahoma City, was one of the hardest hit areas, according to authorities.
"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," Sheriff Booth said, according to The Associated Press. "It's pretty bad. It's pretty much wiped out."
Norman Regional Health System, which serves south central Oklahoma, received five patients with tornado-related injuries, according to spokeswoman Kelly Wells. Three are in critical condition and two others are "walking wounded."
The patients were trapped under debris and have bruises, lacerations, head and internal injuries, Wells said.
Gov. Mary Fallin declared an emergency for 16 Oklahoma counties that suffered from severe storms and flooding during the weekend. Fallin estimated Sunday that more than 20,000 homes and business are without power. Various agencies that coordinate during emergencies were spread thin tending to the storm's devastation.
"We had so many communities that had major storms and tornadoes dropping out of the sky, all over the state, a lot going on at one time so, it was pretty hectic," Fallin said.
Chad Bradley told ABC News Radio he spotted a funnel cloud near Wellston, Okla.
"This tornado is huge. I mean, there's no other way to describe it. It is enormous," he said.
Mark Nettles of Carney, Okla., said several employees from his office and their families came to the safe room at the company and bolted the door.
"You could feel the force from underneath the door. There was three of us holding onto the door," Nettles said. "You could hear … everything outside just crumbling up around you."
In northeast Wichita, apartment manager Lisa Akin says destructive hail broke 150 windows in a 176-unit complex and residents are bracing for more bad weather today.
"Everyone's just pulled together to assist, because I think we have another storm rolling in, so we want to get all the windows covered now," she said.
ABC News Radio and The Associated Press contributed to this report.