Heat accused of mysterious death of Californian hiking family

A California sheriff said heat and possibly dehydration were responsible for the death of a family found on a remote trail in August.

Jonathan Gerrish, 45, Ellen Chung, 30, their one-year-old daughter Aurelia Miju Chung-Gerrish and dog Oski died from hyperthermia in Devil’s Gulch Valley.

The announcement comes two months after rescue teams found their bodies in the Sierra National Forest.

Their unexplained deaths had baffled summer hikers in the western United States.

At a press conference Thursday, the Mariposa County Sheriff’s Office said the family was found with an empty 2.5-liter water bag and had no other bottles or water filters.

Temperatures on the day of their hike rose above 109F (42C), officials say.

According to CBS News, the BBC’s partner in the US, Gerrish was from the UK and met Ms. Chung in San Francisco before moving to the small town of Mariposa in 2020.

Their bodies were discovered by rescue teams on August 17 in an area southwest of Yosemite National Park after a friend called authorities to report them missing.

The Mariposa County Sheriff’s Office worked with the FBI, environmental researchers, and toxicologists to determine what killed the family.

They had already ruled out death from lightning, carbon monoxide, carbon dioxide, cyanide, illegal drugs, alcohol, gun “or any other kind of weapon” or suicide.

The FBI is still trying to access Gerrish’s cell phone, Mariposa County Sheriff Jeremy Briese told reporters.

He added that there is no telephone service in the area they were hiking in and that a previous fire had burned trees that would normally have provided shade in some sections of the steep path.

Concerns about water quality in the nearby Merced River have led to speculation that an algae bloom could have killed them, but officials say there is no evidence that the family drank the river’s water.

Other rejected theories included a loss originating from abandoned gold mines that are common in the gold rush region.