Have any of you been following this story? At first, before paying attention to the details, I wondered about familicide.

https://www.sfchronicle.com/bayarea/article/Not-one-clue-The-mystery-is-only-deepening-16401921.php

After reading the article and looking at a topo map, I came to this conclusion...

These are heat-related deaths until proven otherwise. They went on a 7+ mile dayhike with a 1 year old who may have been the first to begin showing signs of heat stress. They may have known of the algae issue (trailhead signs, online/tv news, since they were locals) and only took/used their own water causing further problems if they underestimated how much was needed for a family of four (3 humans, 1 dog) in those conditions. Once down at the river there is a 3.3 mile 2,500 ft climb back up. The temps were up to 109 F. There is said to be not much shade after the 2018 fire. They had little remaining water when found only halfway up the climb. Toxicology is pending.

The dog is a bit of puzzle. Assume it was on a leash, otherwise would have thought it'd take care of itself.

Weird! I hope they crack the case.

Nothing new pertinent to their deaths, but the husband was a Brit.

https://www.dailymail.co.uk/news/article...amily-dead.html

If it was toxic algae I'm still not sure why the baby would die? Babies don't drink water do they? [Note: Obviously I'm not a parent so far as I know!].

One water sample was positive for cyanotoxins downstream of where they were found. Other samples were negative. Gases and blunt trauma were ruled out. One article yesterday said they were again looking at lightning. It may not be easy to prove a cyanotoxin death of a human. It would be the first in the US.

Right after the bodies were found, on a water quality site, they outright listed the deaths as suspected water toxin. Three days later they changed it to suspected "illness" with no physical proof of either.

The heat index that day was up to 111 F and the wet bulb globe temp 89 F. When people are compelled to hike with toddlers in those conditions and they can't use or drink (because of toxin scare) any of the natural waters, what do you think will eventually happen? Heat related deaths happen every year in Grand Canyon and Death Valley.

Phaedrus, the one thing I can think of is if the parents were sick with the toxin and it slowed them down..then the heat took over. Personally, with all of the "signage" about the bad water, I'd be surprised if the parents had any water toxin in their bodies, but we shall see.

I think most of them would be alive if they had gone back down to the water and stayed in it and near it until found or hiked out at night.

Yeah, that could be. But if they died of dehydration or heat stroke you'd think a coroner would have no trouble recognizing that. And would the dog succumb as quickly as a human?

"Making a diagnosis of a heat-related death may be quite difficult at autopsy as commonly found features such as skin slippage, pleural petechiae, and pulmonary and cerebral edema are entirely nonspecific [7]. Only very rarely will a core temperature of a body proximate to the time of death be available, and heat often accelerates decomposition which further complicates post mortem assessment [8]."

https://link.springer.com/article/10.1007/s12024-013-9413-y

There was possibly up to 1.5 days of decomposition. My wonderings about the dog was that he was on a leash and possibly may not leave their sides as he knew something was wrong with the infant and adults..best I can come up with.

Interesting! I guess I really don't know anything about forensic pathology. But I do hope they can unravel the mystery! If for no other reason than to prevent further loss of life.

More food for thought. When you do a hike like they were attempting and you know you have a 2,500 ft climb out, you stock up with water before leaving the river. Other things that may mean they did not drink the water are (hence no toxins to be found in their system)...

1. Little water left for water testing when found.
2. Authorities already saying one positive test was found downstream but no mention of the result of water with family..prob negative
3. Now looking for other things like lightning.

Yes, I could be a little obsessive on this case ; ).

An account of someone else surviving an algae bloom.

https://www.wral.com/jared-lloyd-firsthand-experience-with-an-algal-bloom/19869971/

Seems Anatoxin-a (aka Very Fast Death Factor) was the toxin found in high levels where the family was.

Still no confirmation though.

Interesting!

The positive test in an algal mat for Anatoxin-A (ATX) downstream from the found family was 11.8 µg/L. Algal mats can be positive for 1,000s of units, so that level is low, not high as the media states.
https://mywaterquality.ca.gov/habs/where/freshwater_events.html

The WHO, in their Guidelines on Recreational Water Quality, 2021, gives a WHO guideline value (GV)recreation for Anatoxin A at a level of WHO HBVrecreation = 60 µg/L
(For ATXs, toxicological data were insufficient for deriving a guideline value, but allow deriving an upper bounding value below which health impacts are highly unlikely – that is, a health-based value.)
https://www.ncbi.nlm.nih.gov/books/NBK572631/

Some municipal waters allow ATX at levels of 20 µg/L (Ohio at that level only puts out advisory)
https://en.wikipedia.org/wiki/Anatoxin-a

Few more details, they had a CamelBak.
Anatoxin-A cannot be filtered out of water, and they didn't have one anyway.

https://www.sfgate.com/bayarea/article/toxic-algae-california-family-death-yosemite-16461960.php

6 More Causes of Death Ruled Out for Calif. Family Who Mysteriously Died on Hiking Trail

https://www.yahoo.com/entertainment/6-more-causes-death-ruled-235753599.html

My top scenario is they took all the water from the start (knew they could not use river water), the 1 year old started showing signs of heat stress at the bottom (under age 4 are extremely vulnerable) and they panic-hiked to get out.

Dutch news article.

https://panorama.nl/artikel/459798/amerika-is-een-mysterie-rijker-was-het-dan-toch-de-hond

Translation of the last sentence, only thing haven't read before.

"The most plausible explanation so far is that the dog inadvertently killed itself and its owners by walking into a river with toxic blue-green algae and then shaking itself dry."

*Dutch website.

Ah yes, no idea why wrote Norwegian, know .nl TLD is Netherlands.

Cause of death announcement at 2:00 PM PDT

https://www.sfchronicle.com/bayarea/arti...ry-16549158.php

https://www.facebook.com/mariposacountysheriff/posts/240652671439058

Update:
Cause of death for the humans is hyperthermia and probable dehydration; for the dog is undetermined but heat related.

Wondering if the infant was first to show problems of heat stress and the parents tried to get out of there. No mobile coverage. Should have had a PLB.

That dayhike was doomed from the start now that we have more info on their gear/provisions. Yes, the child was probably most vulnerable followed not far behind by the dog, imo.

The dog cause of death being undetermined may be the result of knowing that anatoxin-a can kill animals and Oski was too decomposed to properly rule it out.

It is so tragic to see a group of 4 die this way that, in two months, I never saw one mention (over multiple websites) of that certain award given to those who make this type of mistake and don't make it.

In that cause of death announcement it didn't really sound like they gathered more info than they already had. It was more like they threw up their hands and guessed heat.

109 degrees that day.

With 35 assisting agencies to rule out a multitude of violent and nonviolent causes over two months in a group death in extreme weather where no obvious signs of foul play are seen, this case was probably one of the most thoroughly investigated deaths in my lifetime....that is hardly throwing their hands up.

Because of the circumstances, it was always going to be heat-related until proven otherwise, and 35 assisting agencies could not prove otherwise.

https://www.facebook.com/mariposacountysheriff/posts/313203204184004

Mariposa County Sheriff's Office
February 17 at 3:18 PM ·
Final Update on Gerrish / Chung Family

After multiple months with the FBI computer/phone forensic team, the Mariposa County Sheriff’s Office has obtained details from Jonathan Gerrish’s phone.

In October of 2021 we released the cause of death determined by the Pathologist. This was based on autopsy results, our investigation, and a multitude of toxicology/scientific test results. The cause of death for Jonathan Gerrish, Ellen Chung and Aurelia “Miju” Chung-Gerrish was determined to be Hyperthermia, and probable dehydration due to, environmental exposure. Hyperthermia- The condition of having a body temperature greatly above normal.

Using the information extracted from the phone we were able to re-create the path and timeline based on the GPS locations. The details found on the phone support the findings of a heat related incident.

Phone Results Photos: Gerrish & Chung took multiple photos throughout their hike. The following are noted on the map provided
Photo / Video 1- 7:44am – Taken just a few yards from the trail head
Photo 2- 8:00am- Trail Photo
Photo 3- 9:05am- Photo of the River
Photo 4-12 - 9:35-9:39am Photos of the river and of each other
Photo 13- 10:00am Selfie style family photo
Photo 14- 10:16am Selfie style family photo
Photo 15-16 -10:29am Creek / River photo
Photo 17- 12:25pm- Screen shot of location from Trail App

Text Message Attempt:
The following text message was attempted but not successful due to not having cellular service on the area.
11:56am- “{name redacted} can you help us. On savage lundy trail heading back to Hites cove trail. No water or ver (over) heating with baby.”

Phone call Attempts:
The following phone calls were attempted to multiple phone numbers, not including 911. There is no service in the area, therefore the calls were never connected.
Call 1- 12:09:20pm
Call 2- 12:35:48pm
Call 3- 12:36:06pm
Call 4- 12:36:19pm
Call 5- 12:36:24pm

“The cell phone data results were the last thing both the family and detectives were waiting on. The extracted information confirms our initial findings. I am very proud of my team and our partner agencies for all the work they put in. Their dedication has allowed us to close this case and answer lingering questions the family had, bringing them a little peace.”- Sheriff Jeremy Briese

Sad. I imagine that even if they had reception for any of those calls, it wouldn't have changed the outcome.

The heat load in Arizona deserts can e unbelievable, especiallu if you are not acclimatized.

Doing a SAR mission in Tucson on a dy when the temp "only"reached 90F, may companion and I ran through 3 1/2 gallons of water, starting about noon, hiking swiftly uphill over 6 miles on a south facing slope, finally reaching a known dependable water source. We were dehydrated and drank deeply. That was an extreme situation, but you get the drift.....