Lake Tahoe: Six people were killed and two remain missing after a recreational boat capsized in Lake Tahoe during a sudden storm that brought freezing temperatures, 8ft waves, and gusts of wind reaching 35mph (56km/h) on Saturday afternoon.

The vessel, identified as a 27-foot Chris-Craft Launch 27, overturned near D.L. Bliss State Park shortly after 3pm, according to the El Dorado County Sheriff’s Office. Authorities said the group of 10 was caught off guard by the rapidly worsening weather, which caused the lake to turn violent within minutes.

According to the sheriff’s office, the victims have not yet been identified. Two survivors were rescued from the frigid waters and taken to hospital, where they are being treated for hypothermia and other injuries.

Emergency crews responded to a distress call reporting a capsized boat at around 15:00 local time. Officials said the lake, already roughened by intense winds, grew even more dangerous as temperatures plummeted and snowfall began in the surrounding Sierra Nevada mountains.

According to the U.S. Coast Guard, the boat was struck by a large swell in the turbulent waters as the weather system intensified.

The Coast Guard launched an extensive rescue effort, deploying teams across more than 390 square miles over a 12-hour period before suspending the search on Sunday morning.

Meanwhile, the El Dorado County Sheriff’s Dive Team and Search and Rescue unit continued combing the area around Rooster Rock, a jagged lakeside formation near a steep underwater drop-off over 300ft deep.

Lake Tahoe, straddling the California-Nevada border, is the largest alpine lake in North America and has an average depth of around 1,000ft, according to the University of California, Davis.

The Reno Gazette Journal reported that air temperatures had fallen sharply to near freezing on Saturday afternoon, with rain and snow affecting the Sierra region surrounding the lake.

Authorities have not yet released the identities of the deceased or the missing. The incident is being described as one of the most tragic boating accidents in recent memory for the Lake Tahoe region.