BLENCOE, Iowa—When the howling winds finally died down, the Boy Scouts—true to their motto, “Be Prepared”—sprang into action.

Putting their first-aid training to use, they applied tourniquets and gauze to the injured. Some began digging victims from the rubble of a collapsed chimney. And others broke into an equipment shed, seized chainsaws and other tools, and started clearing fallen trees from a road.

Dozens of the Scouts, ages 13 to 18, were hailed for their bravery and resourcefulness Thursday, the morning after a twister flattened their camp in Iowa and killed four boys.

“There were some real heroes at this Scout camp,” Gov. Chet Culver said, adding that he believes the Scouts saved lives while they waited for paramedics to cut through the trees and reach the camp a mile into the woods.

The 93 boys, all elite Scouts attending a weeklong leadership training session, had taken part in a mock emergency drill with 25 staff members just a day before the twister hit.

“They knew what to do, they knew where to go, and they prepared well,” said Lloyd Roitstein, an executive with the Mid-America Council of the Boy Scouts of America.

Killed were Aaron Eilerts, 14, of Eagle Grove, Iowa, and Josh Fennen, 13, Sam Thomsen, 13, and Ben Petrzilka, 14, all of Omaha, Neb. Roitstein said all four had taken shelter in a building that was leveled, and all of them were found near its collapsed stone chimney. The governor said the cause of death had not been determined.

At least a dozen people remained hospitalized Thursday with everything from bruises to spine and head injuries.

At the campsite, a pickup truck had been tossed on its side. Tree limbs rested on top of the Scouts’ tents. Trees were flattened. And the one-room multipurpose building where the Scouts died was a pile of cinderblocks and chimney stones.

Boy Scout officials said the campers had heard the severe weather alerts but decided not to leave because a storm was on the way.

“They were watching the weather and monitoring with a weather radio, listening for updates,” said Deron Smith, a national spokesman for the organization. “The spot they were at was the lowest spot of camp. It was deemed to be the safest place.”

A group of Scouts who had set out on a hike had returned to the camp before the storm hit, Smith said.

On the other side of the state, 3,200 homes were evacuated from flood-stricken Cedar Rapids, where rescuers removed people with boats, officials estimated 100 blocks were under water, and a railroad bridge over the flooded Cedar River collapsed.

In Albert Lea, Minn., 90 miles south of Minneapolis, a man died Thursday after his vehicle plunged from a washed-out road and was submerged in floodwaters.

Also Thursday, several Kansas communities began cleaning up from tornadoes a day earlier that killed at least two people, destroyed much of the small town of Chapman, and caused extensive damage on the Kansas State University campus in Manhattan.

Meanwhile, tales of heroism emerged from the Iowa camp.

Roitstein said a group of Scouts pulled the camp ranger and his family from their destroyed home. Doug Rothgeb of Omaha said his 15-year-old son emerged from a ditch where he had taken cover, then joined other Scouts to break into the equipment shed.

Fourteen-year-old Zach Jessen of Fremont, Neb., said that before the storm struck, someone spotted the rotation in the clouds and a siren sounded in the multipurpose building, which had tables and a TV in addition to a fireplace. Jessen said he and others managed to get Scouts out of their tents and indoors just before the tornado hit. According to Roitstein, the Scouts took shelter in three buildings.

Jessen said shortly afterward, the door on the multipurpose building flew open and he heard someone yelling to get under the tables.

The National Weather Service said it was an EF3 on the 1-to-5 Enhanced Fujita scale of tornado intensity, with an estimated wind speed of 145 mph. The twister cut a path estimated at 14 miles long. Homeland Security Secretary Michael Chertoff toured the camp and said it appeared that the Boy Scouts “didn’t have a chance” and that the tornado came through the camp “like a bowling ball.”