Jefferson City, Missouri, was among the worst-hit areas as the capital took a direct hit from what the National Weather Service called a "violent" tornado Wednesday night. The tornado had a preliminary rating of EF-3, with winds up to 160 mph, National Weather Service officials said Thursday.
While no fatalities were reported in Jefferson City, three people were killed near Golden City, Missouri, from what officials say may have been a long-track tornado.
"Those are the only three [fatalities] we know of at this time," Parson said. "There's nobody missing that we know of ... that's a good thing."
"We were very fortunate last night that we didn't have more injuries than we did, and we're very thankful that we didn't have any more fatalities than we did," Gov. Mike Parson said. "You never know what this weather is going to do."
As storms crossed the Plains this week, bringing over 90 reported tornadoes, at least seven people were killed in three states.
Four people died on Tuesday, including one woman killed after a tornado hit her home in Iowa. Two others died in a car accident in heavy rain near Springfield, Missouri, and one woman drove around a barricade and drowned in Oklahoma.
While no one in Jefferson City was killed from Wednesday night's tornado, at least 20 people in the area were transported to hospitals to treat injuries, said officials.
"There was a lot of debris flying, we had trees [flying]," said Jefferson City Police Department Lt. David Williams, describing what caused the injuries. "At this point, nothing in the serious [injury] declaration, as I've been told by emergency services."
Tornado sirens went off in the city, which has a population of about 42,000, at 11:10 p.m. on Wednesday, and the first damage in Cole County was reported at about 11:38 p.m., according to Jefferson City Police Department Lt. David Williams.
Williams also said they had received multiple calls of people trapped in their homes.
"We realize that we still have a lot of things we have to do," Williams said at a news conference Thursday morning.
Searches were ongoing in Jefferson City mid-day Thursday, as was the flooding threat. Levees may be at their max at about 1 p.m. local time, warned Williams.
Parson said that due to damage sustained by some state buildings in Jefferson City, only essential state employees are being asked to report for work Thursday. Others are being urged to stay at home.
ABC News' Ahmad Hemingway, Melissa Griffin and Emily Shapiro contributed to this report.