Two women were thrown from a raft and drowned near Denali National Park and nine other people who tried to rescue them were treated for hypothermia.

The women, both 75, were in a raft with five people on a 13-mile scenic tour of the Nenana River on Saturday night, said State Trooper Bill Tyler.

"They hit a swell in the water and then went into a whirlpool. The raft was literally just sucked down," Tyler said.

The women were the only ones thrown from the raft.

Two other rafts came around a bend in the river, saw the victims in the water and tried to help. By the time troopers arrived, 18 people were wet and cold as they waited on the riverbank. The temperature was about 38 degrees. Nine were treated for mild hypothermia.

The women were identified as Eloise Hubbard of Doraville, Ga., and Doris North of Decatur, Ga.

The tour company, Alaska Raft Adventure, suspended operations and was investigating the accident, said manager Bob Seney.

He said the company hasn't had an accident in the 10 years it's been offering tours of the river, which forms the eastern boundary of the park. Everyone was wearing insulated suits and flotation devices, he said.