In Illinois, Tornado's Devastation Sinks In Steve Jahnke/The Southern Illinoisan, via Associated Press Damaged homes in Harrisburg, Ill., where six people were killed and about 100 injured on Wednesday. At least six other people in the storms' paths died. HARRISBURG, Ill. - As a curfew lifted on Thursday morning in this small, battered city, the scope of destruction from a powerful tornado a day earlier began to sink in. Residents sifted through piles of debris where their houses had stood in search of photo albums, prescription bottles, prom dresses, anything. A strip mall sat crumpled, only parts of signs left to hint at what it had been. And word began spreading about the identities of six people who died here in Harrisburg, a community of about 9,000 where most people know one another. "I've heard three names so far, and I knew them all," said Dave Bramlet, 49, who said he considered himself fortunate even as he surveyed a commercial building he owned where pieces of the roof were stripped away, a nearby garage vanished and a giant crack ran down one brick wall. That's what it's like in a place like this. No one's not going to know them. It's hit us all. The devastation here, in far southern Illinois, may have been the worst in a powerful storm system that tore through parts of the Midwest and South on Wednesday, killing at least 12 people. Tornadoes and strong winds tore off roofs, downed power lines, tossed mobile homes and injured scores of people from Kansas to Kentucky, according to the National Weather Service. In Harrisburg, in addition to the six people who died - many had been in or near an apartment complex area that was torn apart - about 100 more were injured, some gravely, sheriff's officials said. The tornado, gauged preliminarily as having wind speeds around 170 miles per hour, touched down here around 5 a.m. Wednesday, moving swiftly and cutting a path that city officials have described as several hundred yards wide. Warning sirens had gone off here, and some residents described waking even before the sirens to text messages with warnings from local authorities. The pre-dawn timing of the storm was a double-edged sword: thankfully, officials here said, few people were on the roads at such an early hour or inside the dozens of businesses that were crushed; sadly, though, others may have been asleep and never heard the warnings at all. "I was barely awake," said Diana Turner, 62, who heard the sirens, got up, and almost instantly found herself buried inside her trailer. I just kept hollering, and I could hear my husband hollering from where he was buried. I finally felt some air rushing in, and crawled toward that. I don't know how I got out. Ms. Turner's husband emerged, too, to a world of flashing emergency vehicle lights, power lines all around, and what was left of the trailer's bedroom perched, 20 feet up, in a tree. "After the sirens went off, there was a cracking sound, then everything lit up pretty as could be and my place just exploded around me," Charles Turner, 71, recalled, tears pooling in his eyes. Everything went black, and I thought that was it, I was done. Mr. Turner was treated at a local hospital and released, but even the local hospital sustained some damage and had to move patients to safety. Officials said more than 250 homes were damaged here, and that power was out for almost half of the city, but only about a dozen people stayed at a makeshift shelter overnight. More people stayed with family or friends; other residents offered to open their homes even to strangers. Outside the immediate path of the storm - and sometimes just a single house away - little or no damage was visible. The intense late winter storm system, which resulted from cold air from the Rocky Mountains mixing with warm air from the Gulf of Mexico, also killed at least three people in southern Missouri, according to state officials. Moving east Wednesday night, storms tore roofs from buildings and flattened trees in eastern Tennessee, leaving at least three people dead. The sound of warning sirens and the sight of devastation provided unnerving reminders of the fierce unpredictability of the skies in this part of the country. Last year, 550 people were killed by tornadoes, making it the deadliest season in 75 years, according to the National Weather Service. The worst of those storms leveled much of Joplin, Mo., just east of several of the communities where people were digging out on Wednesday. Monica Davey reported from Harrisburg, and A. G. Sulzberger from Kansas City, Mo. Steven Yaccino contributed reporting from Chicago, and Emma Fitzsimmons from New York.