Robbie Harvey, who went to search the apartment block, said he was "surprised nobody is dead."
"We just got done searching a house and the only thing standing is a front wall," Harvey added.
Tiffany Hudson, who lives in the Moorings complex, said: "We knew there was a storm coming but we didn't know it would be this bad. So the lights started flickering. I guess it just bounced right over us and hit the buildings next to us."
Almost 7,400 customers were without power in the Florida with almost 25,000 in the dark in Georgia, along with 14,000 others in Louisiana and 12,000 in Alabama, utility companies reported beginning at 5 a.m. Wednesday.
As of 10:15 a.m., Illinois saw more than 29,000 outages and Missouri over 39,500 outages, with the St. Louis area getting the bulk of the reports.
Two people were killed earlier as a tornado touched down near the Sugar Hill RV Park northwest of Convent, Louisiana. At least 30 people were treated at hospitals, seven of them in critical condition, said Brandon Keller, a spokesman for the St. James Parish Sheriff's Office.
A third person was killed in Lamar County, Mississippi, county Coroner Cody Creel told NBC News, identifying the man as Harris Dale Purvis, 73. The National Weather Service said radar indicated a possible tornado at the scene, where a mobile home was destroyed.
The same system was also expected to cause heavy snow in the Midwest Wednesday as it met colder air from Canada.
"In St. Louis, Chicago and areas almost as far as Detroit there could be 6 to 12 inches if not 18 inches of snow," Weather Channel lead forecaster Kevin Roth said. "During the daylight hours the temperatures should be around the freezing mark but once the sun goes down there could be icy patches and certainly snow on the roads."
The tornado threat in the Southeast will be mainly over by about 8 p.m. Wednesday as the storm system moves on, he said. "It's still a formidable tornado threat for February. The wind threat is pretty high and it will be very blustery all the way up to the Northeast," Roth added.
More than 1,000 flights were canceled in and out of Chicago's two major airports as of Wednesday morning, with dozens of other flights at O'Hare and Midway airports delayed, according to FlightAware.com.
Dozens of schools in the Chicago area and northwest Indiana also closed Wednesday, while all of the St. Louis public school system shut down because of the weather.