Concerned that Midwesterners might be complacent after repeated tornado warnings came to nothing, forecasters issued a sternly worded alert, well in advance, that weekend storms could prove fatal. The warnings caught Larry Hill's attention. The 72-year-old kept an eye on television weather reports and was barricaded inside a closet by the time a tornado ripped the roof off his home in the southwest Iowa town of Thurman. "We'd been on the lookout for it for three days," he said Sunday morning as he sifted through the remains of his home. That twister was one of dozens that strafed the region on Saturday and Sunday. The National Weather Service's Storm Prediction Center in Norman, Okla., which specializes in tornado forecasting, had warned more than 24 hours ahead of a possible "high-end, life-threatening event." In the end, only one proved fatal. "We can't do this with every event," said the prediction center's Ken Miller, noting that it's not easy to predict which storm systems could pose a threat to life and property. In south central Kansas, Sedgwick County Emergency Management Director Randy Duncan credited the dire language of the warnings for saving lives. Eric Francis/Getty Images About 100 homes were damaged in a Wichita mobile home park, but no serious injuries or fatalities were reported. People listened," Sedgwick County Commissioner Tim Norton said. One northwest Oklahoma town was not so fortunate. As a monster twister bore down, cloaked in darkness in Sunday's early hours, Woodward's 20 outdoor tornado sirens did not sound - they had been knocked out when lightning struck a tower used to activate the system. Frank Hobbie and his daughters, aged 5 and 7 years, died when the tornado hit the mobile home park where they lived, as did Darren Juul and a 10-year-old girl at a home a few miles away. State medical examiner's office spokeswoman Amy Elliot said no other details were available but that a critically hurt child was airlifted to a Texas hospital. Oklahoma Department of Emergency Management spokeswoman Keli Cain said early Monday that a sixth person had died following the Woodward tornado, although she could not immediately provide details of the victim's age or gender, nor of the circumstances of the death. It was not clear if the sirens could have prevented the deaths had they sounded. Many residents in Tornado Alley have grown up counting on sirens to warn them when a twister has been spotted on the ground, but emergency officials say that can be one of the least reliable methods, especially when a tornado hits at night.