Authorities said eight of the nine skiers reported missing after an avalanche near California’s Lake Tahoe have been found dead, with the ninth skier still missing but also presumed deceased.

The avalanche was reported near Castle Peak in Nevada County, north of Boreal Mountain Ski Resort, around 11:30 a.m. Tuesday as a heavy snowstorm moved through Northern California, bringing blizzard conditions to higher elevations.

A total of 15 backcountry skiers were involved in the avalanche, the Nevada County Sheriff’s Office reported, with six of those people surviving and being rescued from the site.

Nine people were still missing as of Wednesday morning, officials said. Search efforts intensified on Wednesday as crews looked to take advantage of a break in the weather.

The Nevada County Sheriff’s Office announced at a press conference later Wednesday morning that eight of the nine missing skiers had been found dead. Search efforts were still ongoing for the last missing skier, but sheriff’s officials said they are presuming that the missing person has also died due to the condition of the scene.

Blackbird Mountain Guides stated that the group was returning from a three-day trip at Frog Lake. The group included four ski guides and 11 clients, the company said.

Of the six people rescued, the sheriff’s office said two have been hospitalized for treatment. The sheriff’s office stated that the survivors were one man and five women, ranging in age from 30 to 55 years old, with one of the six people being a Blackbird Mountain Guide. One of the injured survivors was stabilized, authorities said, while the other was still receiving treatment.

Sheriff’s officials noted that none of the bodies of the eight people found dead have been removed at this time. Search crews have placed avalanche poles so that the bodies can be found again when conditions permit, officials said.

An Avalanche Warning, with the danger rated as “high,” was in effect at the time of Tuesday’s incident, according to the Sierra Avalanche Center. Even into Wednesday, search crews were dealing with elevated avalanche risks and treacherous conditions.

Officials underlined the danger of the backcountry where Tuesday’s avalanche took place, referencing the January avalanche that also killed a snowmobiler near Castle Peak.