A tornado tore through a Boy Scout camp in the remote hills of western Iowa yesterday evening, killing at least four people, injuring 40, and setting off a frantic search to reach others trapped by piles of debris and fallen trees.

Thomas White, a scout supervisor, said that he dug through the wreckage of a collapsed fireplace to reach victims in a building where many scouts had taken shelter.

“A bunch of us got together and started undoing the rubble from the fireplace and stuff and waiting for the first responders,” White told KMTV in Omaha, Nebraska.

“They were under the tables and stuff and on their knees, but they had no chance.”

The tornado struck the Little Sioux camp at 6.35pm local time (2335 GMT), during a violent lightning storm and driving rain. A search and rescue team had to cut its way through branches to reach the camp where the 93 boys, ages 13 to 18, and 25 staff members were attending an annual “Pohuk Pride”, week-long junior leadership training course.

Taylor Willoughby, 13, of Bellevue, Nebraska, said that several scouts were getting ready to watch a film when someone screamed that there was a tornado. Everyone in the building hunkered down, he said, but windows smashed all around them.

He said he saw another scout with his head split open. “It was a pretty gruesome image,” he said.

“We are profoundly saddened ... our heart goes out to all of the families and the children affected by this horrific tragedy,” said Chet Culver, the Governor of Iowa.

The weather service had issued two warnings minutes before the tornado hit, said Mr Culver, but it was not clear whether the camp had sirens.

He added that three people were believed unaccounted for, but a spokesman for the rescuers, Russ Lawrenson, said that all the victims had been found.

Injured campers were taken to five local hospitals as parents of campers gathered in a nearby church awaiting news.

Gayle Jessen of Fremont, Nebraska, said that her 19-year-old son Zach was a staff leader at the camp. He called his parents to say he had a bruise on an arm and was being treated at a hospital.

“I’m so relieved my son is OK,” Jessen said. Her husband had headed to the hospital to pick up their son.

The camp was being secured by the National Guard and police, as search and rescue teams continued to sift through debris.

Today there was a scene of devastation at the 1,800-acre ranch, which has four cabin shelters, a 15-acre lake, a rifle range and six hiking trails.

“All of the buildings are gone, most of the tents are gone, most of the trees are destroyed,” said Lloyd Roitstein, president of the Boy Scouts of Mid-America Council. “You’ve got 1,800 acres of property that are destroyed right now.”

“Based on what we were seeing on radar it looked like it could have been a very powerful tornado,” said Daniel Nietfeld with the National Weather Service.

The storm hit as Iowa’s eastern half grappled with flooding in several of its major cities, threatening to stretch Iowa’s emergency response teams to their limits. Inmates in black-and-white striped uniforms were rescued from a jail by boat as the raging Cedar River flooded Vinton and forced evacuations in Waterloo.

Tornadoes also touched down in southern Minnesota and eastern Nebraska, closing a highway and even sending a cow into the air, a witness said.

Along the Mississippi River in Missouri and Illinois, the National Weather Service was predicting the worst flooding in 15 years. Officials from Wisconsin to Missouri were fortifying levees with sandbags, watching weakened dams and rescuing residents from rising water.

High water levels burst through a levee in Indiana burst a levee, flooding a vast stretch of farmland.

Many other tornados have torn through the Midwest in the last month, in what is the peak of the tornado season. But this year so far has been exceptional, with 1,191 tornados that have left at least 113 people dead. It is on course to beat the record for the largest number of tornados, which currently stands at 1,817 in 2004.

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