A California family found deceased in mid-August on a hiking trail near Yosemite National Park likely died due to extreme heat and not algal bloom, which was cited as a possible cause during the investigation.
The cause of death for Jonathan Gerrish, Ellen Chung and their 1-year-old Aurelia “Miju” Chung-Gerrish found deceased on the Savage Lundy Trail Aug. 17 was determined to be hyperthermia, or heat-related conditions linked to abnormally high body temperatures, and probable dehydration likely related environmental exposure, Mariposa County Sheriff’s Office said in a release.
The official cause of death was determined Oct. 15 based on the county pathologist’s completed report that included the autopsy, investigation and toxicology results.
“Heat related deaths are extremely difficult to investigate, and I want to thank you all for being patient with us as we investigated this case. As I’ve mentioned the Gerrish Gung family have been our top priority as we dealt with this horrible event,” Sheriff Jeremy Briese said in an Oct. 21 statement.
The family dog’s cause of death remains undetermined, though evidence points to possible heat-related issues.
The sheriff’s office acknowledged that the Savage Lundy Trail where the family was hiking had been posted by the Sierra National Forest for toxic algae and is known to have mines. Six separate laboratories tested water samples. The testing showed that the water taken from several locations along the South Fork of the Merced River was positive for anatoxin a, which can be toxic to animals.
“We do not have any evidence indicating that Jonathan, Ellen or Miju ingested any of that water. We also know that there has been no recorded death in humans connected with Anatoxin A, we do know that can be deadly to animals,” officials said.
Temperatures ranged between 92-109 degrees Aug. 15, while the family was hiking. The family had an 85-ounce water container that was empty and no other water containers or water filtration systems were found, according to the sheriff’s office.