Snowmobiler dies after falling 900 feet when ice shelf breaks

A snowmobiler died Saturday after unknowingly stepping onto a shelf of ice hanging over Frog Lake Cliffs and falling 900 feet, according to the Sierra Avalanche Center.

The adult male was part of a group of three touring the area just west of the Tahoe-Donner Ski Resort, the Nevada County Sheriff's Office said. Visibility was poor and the edge of the ridge was difficult to see.

When the man took a few steps toward the edge, a large 40-foot section of the cornice broke underneath him, triggering a 100-foot-wide avalanche that swept him "down the slope over cliffs and through rocks and chutes," the Sierra Avalanche Center said in a statement.

A member of a separate party at the bottom of the cliff performed CPR and was unable to revive the victim.

The Nevada County Sheriff's Search and Rescue Team, Cal Fire, Placer County Nordic Search and Rescue and the United States Navy all responded to the incident, according to the sheriff's office.

The man's body was airlifted from the scene by a Navy helicopter originating in Fallon, Nevada, and taken to Renown Regional Medical Center in Reno, officials said.

"Our thoughts, condolences, and sympathy are with all those affected by this tragedy," the Sierra Avalanche Center wrote in a statement. "Our thanks also go out to those who helped with the recovery effort. This incident represents a sobering reminder of the risks that exist in the mountains.

The victim's name is being withheld pending notification of family members, according to the sheriff's office.