Timberline Lodge, Ore ? Nine climbers fell into a crevasse Thursday near the summit of Mount Hood in an accident that killed three and critically injured two others. Rescue efforts took a dramatic turn when a helicopter trying to reach the survivors crashed nearby, tumbling down the snowy mountainside.

The four crew members escaped the battered helicopter, but one was seriously injured, said Chris Bernard, an Air Force Reserve rescue specialist.

The injured climbers and helicopter crew members were taken to hospitals in Portland, about 50 miles away, said Angela Blanchard, spokeswoman for the Clackamas County Sheriff’s Department. By late evening, the rescuers were working to recover the three bodies.

The Pave Hawk helicopter was attempting to bring up a climber on a gurney attached to a cable when it started to lose altitude. A crew member released the cable just before the pilot pulled away from the ridge.

Its refueling probe jutted into the snow, and the helicopter careened sideways down the mountain. Its rotor blades sheared off, and it rolled about 1,000 feet before coming to a rest at the base of Crater Rock.

Three separate groups of climbers were ascending the 11,240-foot mountain and were about 800 feet from the summit when the accident occurred about 9 a.m. A climber who was beneath the crevasse used his cell phone to call for help.

The chain reaction began when two climbers at the front of the pack slipped, falling into climbers behind them. They all crashed into the next group of climbers, and everyone tumbled into the crevasse, said Cleve Joiner, who called for help.

“The only thing I can compare it to is hockey players who throw themselves on the ice to block a shot,” Joiner said. “Everybody was sliding on the ice, and then they disappeared.”

Joiner, the assistant fire marshall at the Tualatin Valley Fire & Rescue department, was among five people from the department who were climbing. His 14-year-old son was among the climbers who fell in the crevasse, but he wasn’t seriously injured.

“When I found out he was alive, it was an emotional moment,” Cleve Joiner said. “I just kind of fought back the tears and carried on.”

By late evening, all of the injured were being evaluated at hospitals, Blanchard said. One helicopter crew member was in critical condition with internal injuries. Two climbers were in serious condition one had a head injury, and another had several broken bones.

The helicopter went down nearly five hours after the climbers fell. Rescue teams who were on their way up to the crevasse on foot and in snow vehicles made their way to the crash site.

The weather was sunny and winds were calm, easing the task of helicopter crews, but officials said any high-altitude operation was risky.

Pave Hawk helicopters can operate at altitudes up to 14,200 feet. The Pave Hawk is a modified version of the Army’s Black Hawk helicopter used for search-and-rescue missions.

The helicopter was assigned to the Air Force Reserve’s 304th Rescue Squadron based at Portland International Airport, the Pentagon said.

Mount Hood is extremely popular among experienced and novice climbers. Some 40,000 people fill out permits to climb it every year, state recreation officials said.