Five snowboarders were killed Saturday afternoon in a backcountry avalanche on Colorado's Loveland Pass, authorities said.
Clear Creek County Sheriff Don Krueger said in a statement that six snowboarders were caught in the slide. The condition of the lone survivor was not released, and it was unclear if the victims were still buried.
Saturday's deaths bring the total number of avalanche fatalities in the state to 11 this year, according to the Colorado Avalanche Information Center.
Spencer Logan, forecaster for the center in Boulder, said there have been weak layers in Colorado's snowpack since early January.
"Our last series of storms made them more active again,'' he said. "Over the last week and a half, that area got over 18 inches of snow, so if you melted that that would be 2 inches of water, so that is a heavy load.''
Loveland Pass, at an elevation of 11,990 feet, is popular among backcountry skiers and snowboarders. The Colorado Department of Transportation closed U.S. Route 6 as many skiers were headed home from nearby Arapahoe Basin ski resort.
Lisa Clarke Devore, who was headed back to Denver from the resort, told The Associated Press she saw a fire truck and ambulance on the pass, as well two search dogs headed into the area of the slide. She says she saw several ambulances, including one towing snowmobiles, driving toward the pass.
On Thursday, a 38-year-old snowboarder died in an avalanche south of Vail Pass. Eagle County sheriff's officials said the man and another snowboarder likely triggered the slide after a friend on a snowmobile dropped them off at the top of Avalanche Bowl.
U.S. avalanche deaths climbed steeply around 1990 to an average of around 24 a year as new gear became available for backcountry travel. Until then, avalanches rarely claimed more than a handful of lives each season in records going back to 1950.