A huge system of tornadoes and powerful thunderstorms moved across the United States' midsection on Sunday killing at least seven people and causing huge damage, authorities said.

Central Iowa towns of Parkersburg and nearby New Hartford were struck directly by at least one tornado. The impact of the twister will certainly remain in the history of the two small towns. Six people died because of to the powerful winds which wrecked about 50 to 60 houses and other structures.

Rescue teams were deployed in the Parkersburg as soon as possible. They used listening devices as they searched for survivors under the rubble, said Bret Voorhees of Iowa's emergency management.

The seventh victim of the storm system was a two-year-old child. The infant died in the St. Paul suburb of Hugo, Minnesota, near Minneapolis, as a possible tornado struck the city causing huge damage, the local media reported. Nine were reported injured and, according to the town’s Administrator Mike Ericson, at least 20 people are still unaccounted for. However, some of them may have left town for the holiday weekend.

The nine injured are being treated in the local hospital, said Hugo Fire Chief Jim Compton. Although the locals said they saw a tornado touching down in the area, the National Weather Service hasn’t confirmed it.

The apparent tornado hit Parkersburg, a town of about 1,000 west of Waterloo, at about 5 p.m. Sunday. According to local media reports, the winds leveled the southern half of the town.

According to Iowa Homeland Security administrator Dave Miller, there were actually 7 people killed in Parkersburg and two other in New Hartford. The tornadoes also wounded over 50 people.

Among the building hit the hardest by the powerful winds, there was also Parkersburg’s high school. According to The Des Moines Register, the tornado ripped off the roof of the structure.

The town’s elementary school was opened by authorities for evacuees.

Hugo Public Works Director Chris Petree told The Chicago Tribune that he took his family into the basement to shelter from the storm. He added that his house was literarily lifted from the ground and the storm wiped out the second floor.

"I put my daughter down first, my wife on top of her and then I bear-hugged on top of them. All you hear is glass breaking and wood tearing and breaking in half," Petree said.

There have been more than 100 deaths caused by tornadoes and storms this year in the United States so far.

"We've definitely had an unusually high death toll, which is the misfortune of having tornadoes hitting population centers," said Roger Edwards, a meteorologist at the Storm Prediction Centre in Norman, Oklahoma.

The number of tornadoes per year has also grown, the Storm Prediction Centre said. According to their reports, there have been about 1,000 tornadoes this season compared to 500 or 600 by this time in an average year.