The last known victim was trapped under the ruins of a collapsed house in DeKalb County in eastern Tennessee, and emergency workers were readying a recovery operation.
“They can see part of a body,” Tennessee emergency management spokesman Jeremy Heidt told AFP, but without confirming the third death in the state from the tornados.
“There is a collapsed structure on the person and as soon as the site is confirmed safe, a recovery operation is due to begin,” Heidt said, a day after horrendous weather wreaked destruction across the midwest.
Homes were smashed to bits, cars were tossed into lakes, trees were uprooted and shops were reduced to rubble in towns from Nebraska to Kentucky as the powerful system whipped up strong winds, hail and ominous funnel clouds.
The town of Harrisburg, Illinois, was the hardest hit after it was ripped apart by a deadly twister that stayed on the ground for miles, striking while most were still sleeping at around 4:30 a.m. (1030 GMT) on Wednesday.
At least six people were killed and more than 100 injured in Harrisburg, a southern Illinois town with a population of 9,000.
The monster twister packed winds up to 170 miles (270 kilometers) per hour and damaged or destroyed up to 300 homes and 25 businesses, smashing a strip mall to bits and tearing a wall off the local hospital.
Harrisburg mayor Eric Gregg called Wednesday’s destruction and loss of life “devastating” and vowed to provide care for those who were hurt and displaced.
The National Weather Service has received 30 reports of tornadoes in six states since the storm began Tuesday, battering Nebraska and Kansas before rolling eastward to Missouri, Illinois, Indiana and Kentucky.
Severe thunderstorms pounded Alabama, Georgia, Kentucky, Mississippi, North Carolina and Tennessee on Wednesday before the bad weather pummeled toward the eastern seaboard.
Missouri governor Jay Nixon called in the national guard to help with the cleanup after at least three people were killed by tornadoes, which ripped across the southern portion of the state.
Some 545 people were killed by tornadoes in 2011, which was the deadliest tornado season since 1936 and the third-worst on record, according to the national weather service.