More than 20 people have been killed after a devastating tornado sparked a “mass casualty event” in the United States.
At least 14 Americans have died in Kentucky while seven have passed away in Missouri, officials have said.
Tornadoes have also torn through Wisconsin, leaving hundreds of thousands of people without power.
The storm system originally hit Scott County in Iowa, 130 miles south of St Louis, on Friday, Sheriff Derick Wheetley said.
The devastation that has ensued over the last 24 hours has seen roofs torn off buildings, windows destroyed and trees toppled.
Dozens of people are believed to have been injured and in hospital, but the exact numbers have not been confirmed.
And close to 50 million people are still at risk this weekend, meteorologists from AccuWeather have claimed.
Mayor of St Louis Cara Spencer said: "Our city is grieving tonight. The loss of life and the destruction is truly, truly horrendous."
Kentucky officials have described the situation as a "mass casualty event" after storms wrecked Laurel County late on Friday.
“The search is continuing in the damaged area for survivors,” Laurel County Sheriff's Office spokesman Gilbert Acciardo said.
The US National Weather Service warned of further devastation hitting Texas, Kansas and Oklahoma on Saturday.
"Severe thunderstorms producing large to very large hail, damaging gusts, and a couple of tornadoes are expected across the southern Plains," the NWS said.
Midwest tornadoes were also expected to hit Illinois, eventually stretching to New Jersey and the Atlantic seaboard.
Officials continue to assess the damage as rescue efforts remain underway in the hardest-hit communities.
