People walk down a street past damage after a tornado in Greenfield, Iowa, on Tuesday. AP

Multiple people were killed when a tornado tore through Greenfield and left a wide swath of obliterated homes, crumpled cars and splintered trees, while outside the small town, massive wind turbines were buckled and twisted to the ground by the howling winds.

After devastating the town of 2,000 residents, the storms moved eastward to pummel parts of Illinois and Wisconsin, knocking out power to more than 130,000 customers in the two states.

Greenfield's hospital was among the buildings that were damaged in the town, which meant that at least a dozen people who were hurt had to be taken to facilities elsewhere, according to Iowa State Patrol Sgt. Alex Dinkla.

"Sadly we can confirm that there have been fatalities,” Dinkla said at a news conference Tuesday night, without specifying how many. "We’re still counting at this time.”

He said he thought they had accounted for all of the town’s residents but that searches would continue if anyone was reported missing. The Adair County Health System said in a Facebook post Tuesday night that it had set up a triage center at the Greenfield high school and that people who need medical attention should go there.

People examine damage after a tornado moved through Greenfield, Iowa, on Tuesday. AP

The tornado destroyed much of Greenfield, which is located about 55 miles (90 kilometers) southwest of Des Moines, during a day that saw multiple tornadoes, giant hail and heavy rain in several states.

Authorities announced a mandatory curfew for the town and said they would only allow residents to enter Greenfield until Wednesday morning. They also ordered media representatives to leave the city Tuesday night.

In the aftermath of the storm, mounds of broken wood from homes, branches, car parts and other debris littered lots where homes once stood. Some trees still standing were stripped of their limbs and leaves. Residents helped each other salvage furniture and other belongings that were strewn in every direction.

Rogue Paxton said he sheltered in the basement of his home when the storm moved through. He told WOI-TV he thought the house was lost but said his family got lucky.

"But everyone else is not so much, like my brother Cody, his house just got wiped,” Paxton said. "Then you see all these people out here helping each other. ... Everything’s going to be fine because we have each other, but it’s just going to be really, really rough. It is a mess."

Workers search through the remains of tornado-damaged homes in Greenfield, Iowa, on Tuesday. AP

Multiple tornadoes were reported throughout the state, and one also apparently took down several 250-foot (76-meter) wind turbines in southwest Iowa. Some of the turbines caught fire, sending plumes of smoke into the air.

Wind farms are built to withstand tornadoes, hurricanes and other powerful winds. According to the U.S. Department of Energy, turbines are designed to shut off when winds exceed certain thresholds, typically around 55 mph (89 kph). They also lock and feather their blades and turn into the wind, to minimize the strain.

Greenfield bills itself on its website as a "friendly wave as you walk” type of place with tree-lined streets - before the storm - and as the "perfect place to grow.”

Mary Long, the owner of Long’s Market in downtown Greenfield, said she rode out the storm at her business in the community’s historic town square, which largely escaped damage. Long said there appeared to be widespread damage on the east and south sides of town.

"I could hear this roaring, like the proverbial freight train, and then it was just done,” she said.

Associated Press