Hiking family’s cause of death still a mystery after autopsies in California

What could cause two adults, a baby and a dog to suddenly die together in the middle of a hike through the woods?

Investigators say they’re stumped by the mysterious deaths of a young family in the Sierra National Forest of California, after an autopsy failed to determine what killed them on their hike.

John Gerrish, his wife Ellen Chung, their one-year-old daughter Miju and their dog, Oski, were found dead on a hiking trail in northern California last Tuesday, one day after they were declared missing.

The Mariposa County Sheriff’s Office immediately deemed the case to be “bizarre,” particularly since there were no obvious injuries to the bodies.

“You come on scene and everyone is deceased,” Mariposa County Sheriff Jeremy Briese told the San Francisco Chronicle last Friday. “There’s no bullet holes, no bottle of medicine, not one clue… It’s a big mystery.”

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Gerrish was found in a seated position with his daughter and his dog beside him, while Chung was found farther up the hillside path that they’d been hiking, Briese said.

There was also no suicide note, officials said last week.

Investigators treated the scene as a hazardous materials situation at the time.

The mystery only deepened after initial autopsies were conducted. Coroners found no clear cause of death, though they are still awaiting toxicology results that could take several weeks.

In the meantime, authorities have been mulling a range of poisonous possibilities, including toxic algae and deadly gas released by old mines near the forest’s scenic Hite Cove trail.

Gerrish, 45, was a British-born software engineer, while Chung, 31, was a yoga instructor. The couple reportedly moved to Mariposa to work remotely and enjoy the outdoors, friends and family told the Chronicle.

“From everyone we talk to they were extremely happy,” Briese said. “They were able to work from home and enjoy nature, and in the short time they were here they made a lot of friends.”

Investigators have not narrowed in on a possible cause of death, though they have cast doubt on a few possibilities. Dehydration is unlikely because the family had water with them, the Chronicle reports. Snake bites also seem unlikely due to a lack of injuries. There were also no signs of trauma.

Authorities have searched the area for old mine shafts but none have been found to date.

They’re also considering the possibility that the family might have died from toxic algae, after forestry officials issued a warning about algal mats on the nearby Merced River last month. Algal mats can be dangerous if touched or consumed with water.

Briese says it could be weeks before more details emerge.

“It’s just so tragic and mysterious,” family friend Steven Jeffe told the Washington Post. “We’re just devastated by the loss.

“But I think the community is more like, ‘What the heck happened?’”