Three people were killed in an avalanche in Washington near Stevens Pass ski area Sunday afternoon, ESPN.com has confirmed. The three were skiing in a group of 13 friends that included both local and visiting skiers, according to ESPN Freeskiing editor Megan Michelson, who was among the skiers in the group.

The group was descending a popular route outside the resort boundary accessed via a 10-minute hike from a backcountry gate off the top of the Seventh Heaven chairlift. The avalanche was triggered about noon by one of the skiers who perished in the slide.

Freeskiing World Tour head judge Jim Jack, Stevens Pass Director of Marketing Chris Rudolph and skier John Brenan -- all residents of Leavenworth, Wash. -- were confirmed as the skiers who died in the slide Sunday afternoon.

An ambulance responds to the scene at Washington's Stevens Pass, where three people were killed in an out-of-bounds avalanche Sunday afternoon. Meg Haywood-Sullivan

According to both Michelson and pro skier Elyse Saugstad, who was also in the party of 13, the slide occurred after a number of skiers had already skied the top section of the line, which funnels into the Tunnel Creek drainage. Saugstad was one of four skiers -- along with Rudolph and Brenan -- waiting in the trees approximately 300 vertical feet below the top of the line when the slide was triggered.

Michelson, waiting at the top, said the initial slide was approximately 30 feet wide and three feet deep at the crown. It quickly propagated wider into the trees where Saugstad was standing, sweeping away her and two of the other skiers who died. The fourth skier who was standing with them managed to grab hold of a tree and avoid being taken by the avalanche.

Saugstad and the three deceased skiers were carried between 2,000 and 3,000 vertical feet, she and Michelson estimated. Once she was caught, Saugstad immediately deployed an airbag from her backpack, a device she later credited with saving her life. When she came to rest, "I was completely buried except for my head and hands." Both of the deceased skiers she'd been standing with in the trees were found nearby, Saugstad said. One was a few feet from her and the other was approximately 50 feet away. The third deceased skier was carried "several hundred feet" farther down the mountain, Saugstad said.

The remaining skiers who watched the slide from above immediately turned their avalanche transceivers to "search" mode and skied the length of the avalanche track looking for possible victims, Michelson said. They also called for help. While descending the slide path they found two ski poles and a ski but did not locate anyone until they came upon Saugstad, whom they subsequently dug out. "The debris pile at the bottom was massive," Michelson said.

Saugstad estimated she was in the snow for "less than 10 minutes." The group quickly located the three victims but efforts to resuscitate them were unsuccessful.

Stevens Pass was hit by a powerful winter storm leading up to Sunday's avalanche. The resort reported 14 inches of fresh snow overnight and 26 inches in the prior 48 hours. The Northwest Weather and Avalanche Center rated the avalanche danger as "High" on Sunday morning for elevations 5,000 feet and above and warned of "widespread natural and triggered soft and wind slab avalanches" for the area around Stevens Pass, due to heavy snowfall and strong winds. Stevens Pass ski area's base elevation is 4,061 feet and the summit elevation is 5,845 feet.

All of the people in the group were experienced backcountry skiers and were carrying avalanche rescue gear, Michelson said. They were skiing the line in sections, one by one, in accordance with standard safety protocol.

Two hours south, at Alpental -- one section of Washington's Summit at Snoqualmie resort -- a snowboarder was killed Sunday after triggering an avalanche and being swept over a cliff, according to authorities.