By the CNN Wire Staff
(CNN) -- Weary residents may get some good news Thursday as the monster storm system that already battered many Midwestern states and caused a dozen deaths is expected to weaken.
The National Weather Service's Storm Prediction Center downgraded its outlook for severe weather from moderate to slight over the Southeast and Mid-Atlantic. It said there was only a 5% probability of tornadoes through Thursday morning.
The death toll from the enormous storm system that plowed through the Midwest and spawned more tornadoes as it moved east was at 12 late Wednesday, authorities said.
Hardest hit was Harrisburg, Illinois, a town that was thrashed by a pre-dawn killer tornado that packed 180 mph winds. Six people were killed in the southern Illinois city, and many were injured or left with harrowing stories like Justin Hicks.
"When we woke up, half the roof was coming off the house," said Hicks. "We managed to get the small children in the closet, and about the time the small children were in the closet my wife and I noticed the walls separating from the house."
Hicks' home was destroyed but he says it could have been much worse.
"We're very lucky to be alive," he said. "It happened so fast. I woke up to a chaos, and I'm sure a lot of people woke up to chaos. I wasn't expecting it to be that bad."
The dead included four women and two men. The tornado had a preliminary rating of EF4, the second most powerful on the rating scale, according to the National Weather Service.
The twister appeared to have been on the ground for several miles, said Harrisburg Mayor Eric Gregg, and the path of destruction was about three or four football fields wide.
Debris and collapsed houses littered the ground in the southern part of Harrisburg. Commercial and residential buildings were crushed. A tractor-trailer could be seen laying on its side, off the highway.
"It was probably the loudest sound I ever heard," firefighter and storm chaser Brandon Culkin said of the Harrisburg tornado. "The popping sound was like going over a mountain, like when your ears pop, but 10 times worse."
All of the windows in his vehicle shattered as it rolled and rolled, he said.
Darrell Osman lost his mother to the storm. After the twister struck, he ran to her house, only to find nothing left.
"Her house was literally gone," he said.
He found his mother in an ambulance, but she passed away later at a hospital.
Christy Stewart, a local reporter for The Daily Register, said that despite the widespread damage, "the overall response I've felt from people in the community is a sense of hope.
"People are coming together and being very supportive," she added. "Everyone's really surprised... but through all this awful destruction we are seeing a ray of hope."
According to the sheriff's office, some 100 people were injured and between 250 and 300 houses were damaged or destroyed.
Among the structures hit was the Harrisburg Medical Center. CEO Vince Ashley said the tornado took out 80 feet of exterior wall, exposing patient rooms, and a significant portion of the roof.
A smaller tornado caused significant damage in the music resort city of Branson, Missouri.
Branson Mayor Raeanne Presley took cover with her family in the basement before immediately going out to survey the damage.
The city's entertainment district, which boasts 50 theaters, had five or six damaged, she said.
Of the city's 200 hotels, 15 had significant damage.
"We'll be open for business in short order, and we will be helping those who suffered damage to rebuild," she said.
Nearly 200 people were hurt across the region, officials said.
Two twisters were reported Wednesday night near Hodgenville, Kentucky. Winds in excess of 100 mph were reported in northwestern Alabama.
At least six counties in Kentucky also suffered storm damage. A shaken and bruised Steven Vaught of Greenville, Kentucky, recounted how he and his two dogs tumbled when his trailer rolled several times down the hill. They all survived.
"I got up, took two steps off the couch, and then me and the two dogs that were with me and the trailer started rolling down the hill," he said.
The trailer rolled over five times.
"Once it hit the ground on the fifth time, I saw daylight and I was sitting up against the stove," he said.
He retold the story through tears as he reflected on his survival. "It wasn't my time," he said.
An apparent tornado near Cassville, Missouri, left one person dead, the Barry County Sheriff's Office said. That person was thrown out of a mobile home, the sheriff's office said.
One death each has been reported in Buffalo and Puxico, Missouri officials said.
"I woke up this morning and looked outside and saw houses were destroyed," said Steven Scharmanzer in Branson. "I've never seen anything like this in the 20 years I've lived here."
Missouri Gov. Jay Nixon, who declared a state of emergency, said the damage there was in at least the tens of millions, but there were no reported deaths. "We are confident that Branson will be back bigger and better than ever," Nixon said.
An EF2 tornado smashed at least seven miles of the city's commercial strip, leaving 33 people hurt, most with minor to moderate injuries.
The city's convention center and an attached Hilton were damaged, as was a portion of Branson Landing, a large shopping and entertainment complex.
City Administrator Dean Kruithof said about five or six of the city's roughly 40 theaters were damaged.
"We have so many people who want crews in here to clean up, who want to start rebuilding," Kruithof said.
There were also three deaths Wednesday evening in Tennessee, authorities said.
CNN's Logan Burruss, Kara Devlin and Joe Sutton contributed to this report.
