Teen dies after going swimming in California lake

A teenager was found dead after he swam in a lake in California last week, officials said Thursday. 

The Madera County Sheriff's Office said a 19-year-old from Los Angeles County was reported missing Aug. 10 and had been unaccounted for eight hours after he went swimming alone to one of the islands in Thousand Island Lake. He was last seen ashore from a distance by the party he went hiking with, authorities said. 

Search and rescue teams were called, found the teen and requested a naval air station helicopter to provide medical assistance. When the helicopter arrived, the teen was found dead and was taken to Fresno Yosemite International Airport with his father, who went hiking with him, according to authorities. Fresno Airport Police and staff from the county sheriff's office met with them there. 

The Thousand Island Lake is part of the Ansel Adams Wilderness in eastern Madera County, which has an elevation of 9,833 feet, with 10,000-foot peaks surrounding it.  Authorities cautioned their high-country alpine lakes are "extremely cold" even if the valley floor sees 100-degree days. 

"At Thousand Island Lake, the overnight lows are in the low 40's at night, and the lake itself is fed by glaciers from Mount Ritter and Mount Banner, the peaks of which are -/+ 12,000 feet in elevation. Even in the warmer months, the water is extremely cold," the sheriff's office said. 

Madera County Sheriff Tyson Pogue extended his condenses to the victim's family and friends in a statement. 

"Incidents like this are truly heartbreaking, and some of the hardest calls we conduct as first responders," Pogue said.