Snapchat engineer and family found dead on hiking trail killed by dehydration

A California sheriff has revealed a British Snapchat engineer, his wife and daughter died of hyperthermia and probable dehydration while on a hike – ending a mystery that had puzzled people for months.

Mariposa County Sheriff Jeremy Briese held a news conference on Thursday to discuss the mysterious deaths of John Gerrish, 45; his wife, Ellen Chung, 30; their 1-year-old daughter, Miju, and their dog.  

The Northern California family went hiking on a remote trail close to the Merced River in the Sierra National Forest, where they were found dead August 17 after a family friend reported them missing.

The family were found 1.6 miles from their vehicle in temperatures of up to 103 degrees Fahrenheit. 

There was one 85 ounce Camelbak bladder for water with them, which was empty. There were no other water containers with them, Briese said. 

‘The loss of the family is pain beyond words,’ said the family in a statement.

‘When that pain is compacted by lack of knowledge about their death, the questions of where, why, when and how fill the void, day and night.’ 

They thanked the sheriff’s office for having ‘truly gone the extra mile’ in trying to find answers. 

‘Some questions have been answered, and we will use this to help us come to terms with this.

‘They will remain with us wherever we go, or whatever we do.

‘In the future when we sit beneath the trees, hearing the wind soar beneath the branches, we will think of them and we will remember.’ 

Jeremy Briese of Mariposa County Sheriff’s Office held a press conference on Thursday to reveal the cause of death of the family, after months of speculation

Briese showed footage (right) of the ‘rugged terrain’ where the family were found

The Northern California family went hiking on a remote trail close to the Merced River in the Sierra National Forest, where they were found dead August 17 

The bodies of the family of three and their pet were found on the Savage Lundy Trail, 1.6 miles from their parked truck

Briese said that dehydration can cause dizziness and ultimately death. 

Hyperthermia is abnormally high body temperature caused by the failure of heat-regulating mechanisms. 

The cause of death of the family’s dog was undetermined, but i is believed the dog was also suffering from heat-related issues. 

‘Our message to the hiking community is please take into account aquifers as well as geographics,’ he said. 

Gerrish and Chung’s death has mystified investigators for months

He said they did not have water filtration equipment with them. 

‘Prepare appropriately. The community is resilient, the community is safe, but this is an unfortunate and tragic event due to the weather.’ 

The couple were described by friends as experienced hikers, but as relative newcomers to the area.

Briese suggested they may not have been aware how quickly temperatures could rise in the terrain. 

When they began hiking, he said, the temperature was in the mid-70s; when they had gone barely two miles, it was already above 90. 

Mariposa County Sheriff’s investigators have worked with toxicologists, environmental specialists, the FBI and other experts. 

They had already already ruled out the causes being related to a gun or any other weapon, a lightning strike, carbon monoxide, carbon dioxide, cyanide exposure, illegal drugs, alcohol or suicide. 

Briese said there were ‘no apparent causes of death’ when the family was found.

He said the area was known to have mines, and police were concerned about possible environmental hazards. 

An initial theory was that they could have been poisoned by toxic material in the water. 

Toxic algae blooms were discovered around 12 miles downstream from where Gerrish and his family were discovered dead, prompting the Bureau of Land Management earlier this month to close hiking trails and campgrounds along a stretch of the Merced River to the public.

After water samples from the river tested positive for toxic algae, authorities closed 28 miles of the waterway between the towns of Briceburg and Bagby. 

Briese said on Thursday that they used six separate laboratories to test the water.

‘The water was confirmed positive for Anatoxin-A’, said Briese.

Anatoxin-A isa naturally occurring toxin from blue-green algae, also known as Very Fast Death Factor (VFDF). 

‘There was no evidence that the family ingested the toxin,’ he said. 

John Gerrish, 45, and his wife, Ellen Chung, 30, were said to be experienced hikers, but new to the area

The bodies of the family of three and their pet were found on the Savage Lundy Trail, 1.6 miles from their parked truck

The Sierra National Forest in California closed more than a dozen trails, campgrounds and picnic areas, citing ‘unknown hazards’

At around 7.45am on August 15, a witness saw Gerrish and Chung heading to the Savage Lundy Trail in their truck. 

Two days later, the parents, their one-year-old daughter and their dog, Oski, were discovered by on the trail by search and rescue teams.  

Investigators previously revealed that Gerrish was researching the Hites Cove hike on a phone app the day before the family set off on their doomed journey. 

Detectives believe they managed most of a challenging 8.5-mile loop, which included five miles along a steep slope with little shade as temperatures reached 109 degrees, before they died on the hiking trail, about 1.6 miles away from their truck, which was parked at the Hites Cove trailhead. 

A missing person’s report was made at 11pm on August 16 and a Mariposa County sheriff’s deputy discovered their truck at the end of Hites Cove Road at the trailhead around three hours later.

Search teams were deployed on the steep trails and the family were found along the switchbacks leading back to their trucks at 11am on August 17.

Gerrish was a software developer for Snapchat and had previously worked for Google. He graduated from Newcastle University. His American wife, Ellen Chung, was studying psychology and the couple were very active

There were few clues for detectives at the scene and no signs of foul play, such as trauma, the police said.

No significant evidence was found in searches of the family home and vehicles, the sheriff’s office said.

Gerrish was a software developer for Snapchat and had previously worked for Google. He graduated from Newcastle University. 

His American wife was studying psychology and the couple were very active and often spent time outdoors or traveling.