Six women killed in the deadliest avalanche in the United States in decades were part of a close group of eight friends on a guided backcountry ski trip when a powerful winter storm triggered a massive slide in California’s Sierra Nevada, authorities and families said Thursday, as investigations began into why the tour continued despite avalanche warnings.The women were part of a close group of eight friends on a three day backcountry skiing trip near Frog Lake. Three professional guides are dead or presumed dead, bringing the total fatalities to nine. Two of the friends survived and were rescued along with four others, including one guide.“We are devastated beyond words,” the families said in a statement released through a spokesperson. “Our focus right now is supporting our children through this incredible tragedy and honoring the lives of these extraordinary women. They were all mothers, wives and friends, all of whom connected through the love of the outdoors.”The six women who died lived in the Bay Area, Idaho and near Lake Tahoe. They were identified as Carrie Atkin, Liz Clabaugh, Danielle Keatley, Kate Morse, Caroline Sekar and Kate Vitt. The families asked for privacy and said they “have many unanswered questions.”They said the trip had been carefully organised in advance and that the women carried avalanche safety equipment.“They were experienced backcountry skiers who deeply respected the mountains,” the statement said. “They were trained and prepared for backcountry travel and trusted their professional guides on this trip.”Rescue crews have been unable to immediately recover all the bodies due to dangerous weather. Ashley Quadros, spokesperson for the Nevada County Sheriff’s Office, said it would be at least another day before crews could attempt further recovery operations and continue the search for a ninth person.“We are on the mountain, but they are not going to be able to safely reach them,” she said. “The weather conditions are really dangerous.”Forecasters warned that several more feet of snow could fall around Lake Tahoe, further destabilising the snowpack. The Sierra Avalanche Center cautioned that wind gusts along ridgetops could reach 60 mph and warned of a high risk of large avalanches through at least Friday morning. Tahoe National Forest lands in the Castle Peak area were closed to the public until March 15.The 15 skiers began their trip on Sunday as storm warnings intensified. They stayed in high country huts accessible only by difficult trails.Some of the victims had ties to Sugar Bowl Academy, a private school for competitive skiers and snowboarders on Donner Summit. “This tragedy has affected each and every one of us,” executive director Stephen McMahon said in a statement.California Governor Gavin Newsom said some of his wife’s old family friends were on the trip.“These were some experienced guides that were out there and that’s what’s even more concerning and disturbing,” he said at a news conference.The guides were employed by Blackbird Mountain Guides, which offers mountaineering and backcountry ski trips. The company said it had launched an investigation and was mourning the loss of three members of its guide team.“We don’t have all the answers yet, and it may be some time before we do,” the company said.“This was an enormous tragedy, and the saddest event our team has ever experienced. In addition to mourning the loss of six clients, we also mourn the loss of three highly experienced members of our guide team,” founder Zeb Blais said.Authorities are examining why the tour proceeded despite avalanche warnings. Nevada County Sheriff Shannan Moon said the decision making will be part of the investigation. California’s Division of Occupational Safety and Health is also reviewing whether any workplace safety laws were violated.The Sierra Avalanche Center had issued an avalanche watch on Sunday morning, the first day of the trip, signalling a high risk of large avalanches.Avalanche safety experts say backcountry skiers sometimes venture out even during watches or warnings, as conditions can vary across terrain and decisions often rely on on site snow assessments. It remains unclear whether the guides were aware of the warning at the time, though they are trained to evaluate snow conditions in the field.At least one guide was able to send text messages after the slide. Two of those rescued were taken to hospital and have since been released.The avalanche is the deadliest in the United States since 1981, when 11 climbers were killed on Mount Rainier in Washington state.Separate avalanches in Utah this week also turned deadly. A man riding a snowmobile was killed despite what authorities described as the “courageous efforts” of his young son who dug him out, and another avalanche left a girl in critical condition in Salt Lake County.