8 skiers found dead, 1 still missing after Sierra Nevada avalanche amid extreme weather conditions

NEVADA COUNTY, Calif. – First responders said eight of the nine skiers missing after being caught in an avalanche on Tuesday morning in the Sierra Nevada have died.

The avalanche happened on Castle Peak in the California area Tuesday morning. Six skiers were rescued, eight were found dead and one is still missing, according to authorities.

Officials say this marks the deadliest avalanche in the U.S. since 2010, when the National Avalanche Center first started collecting avalanche data.

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Six people from the party were rescued Tuesday night and two were taken to a hospital, the Nevada County Sheriff's Office said. Of the six people rescued, five were clients, and one was a guide.

The sheriff's office noted that it was initially believed that 16 people went on the trip, but that was later revised to 15.

One person backed out of the trip at the last minute, the sheriff's office said.

Officials said the avalanche happened around 11:30 a.m. local time. Interstate 80 remained closed at the summit of Castle Peak due to a winter storm dumping feet of snow in the Sierra Nevada mountains.

Heavy snow and high winds created periods of whiteout travel and hampered the search Tuesday, with winter storm conditions expected to continue through much of the week.

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"Widespread areas of unstable snow and numerous avalanches are expected today," the Sierra Avalanche Center said. "Avalanches could be triggered from very low on the slope in some areas. Avalanches from above could travel down through treed terrain, often thought of as ‘safe’ during storms."

Travel in the avalanche area is not advised during such extreme conditions. The Sierra Avalanche Center said if travel can't be avoided, use extreme caution and prepare for low visibility around the mountains.

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An avalanche warning remains in effect through 5:00 a.m. local time Wednesday, and the Sierra Avalanche Center said large avalanches are expected to occur across backcountry terrain.

The sheriff's office said the search is ongoing as weather conditions permit.

SNOWMOBILER DIES FOLLOWING AVALANCHE IN CALIFORNIA

An avalanche in the region in early January left a snowmobile trapped in nearby Truckee. A search and rescue mission uncovered the snowmobile buried in snow, but he didn't survive.

This is a developing story. Check back for new updates.