Fatal avalanche triggered by snowboarder, report says

A report recently released from the Utah Avalanche Control Center states the avalanche that killed skier Heather Gross on Dec. 14 at Snowbird ski resort was initiated by a snowboarder.

The unidentified snowboarder was passing along the uppermost slope of Mt. Baldy, an in-bounds run at the resort, when he triggered the avalanche. The center says that avalanche dangers will remain high into Monday.

According to the report compiled by Jim Collinson with the Snowbird Snow and Safety Department, as the slide was set in motion Gross, 27, was attempting to climb up the hill to retrieve a lost ski.

"Warnings were yelled, but when visibility returned, the slope was empty," Collinson wrote.

A cell-phone call to the ski patrol from a witness during the avalanche alerted search crews to the area as skiers and snowboarders in the area began immediately searching for missing people.

The search team responding from Snowbird included dogs, beacons and probes. Additional probes were also provided to those already searching at the scene. At the peak of the search the report states that about 150 people were on site. The large search party and scattered equipment at the scene made locating Gross difficult for the dogs.

Gross was found 58 minutes after the slide had settled three feet below the surface by searchers using a probe. Gross, a graduate student at the University of Utah studying linguistics, was the only person caught in the slide. She was not wearing a beacon or other equipment used to locate avalanche victims, according to the report.

The avalanche occurred the first day the run on Mt. Baldy had been open to the public.

The report compiled by Collinson recounts the avalanche control work that had preceded the slide. On Nov. 20, Dec. 9 and Dec. 14, crews had conducted avalanche control tests using explosive charges in attempts to trigger slides. The report states theses tests issued "no results."

On the day of the slide that killed Gross, crews shot one charge into the suspected starting zone of the avalanche, and another charge into a lower flank of the slope. All five of Mt. Baldy's routes were tested with explosives prior to opening. The tests produced "no significant results," according to the report.

"Prior to the avalanche which occurred at 12:24 p.m. an estimated 300 people crossed the starting zone and or skied the slope that failed," the report states.