The Mariposa County Sheriff’s Office previously said the updates on the deaths of John Gerrish, his wife, Ellen Chung, their 1-year-old daughter, Miju, and their dog, Oski, 8-year-old Aussie/akita mix, would be the final investigative update on the case.
The family was found dead on Aug. 17 on the Savage Lundy Trail near the Merced River in the Sierra National Forest. A friend had reported them missing after Gerrish, a software engineer who formerly worked at Google, failed to report for work.
The area where they were hiking had temperatures between 107 degrees and 109 degrees at one point and there was little shade, Mariposa County Sheriff Jeremy Briese said.
“This is, again, an unfortunate and tragic event due to the weather,” he said. “Heat-related deaths are extremely difficult to investigate.”
The Gerrish family were wearing shorts and tank top attire on the hike and their water container was empty, he said. They were found more than 1.5 miles from their vehicle.
In a statement from the Gerrish-Chung families, they said the loss of their loved ones was exacerbated by the death of a young child.
“The question ‘Why?’ can never be answered and will remain with us,” the family said. “Our hearts will never forget the beautiful lives of Jonathan, Ellen, Miju, and of course, Oski. They will remain with us wherever we go and in whatever we do.”
The deaths stumped investigators as foul play was ruled out. The bodies had no signs of wounds or trauma, authorities said at the time.
High levels of toxic algae in the river was one theory that was looked at. In July, the California Department of Fish and Wildlife warned that “water testing along the Merced River near Hites Cove… show a high concentration of algae bloom.”
Other possible causes that were thought to have been responsible for the deaths were toxic gases in the area.
The deaths led the Bureau of Land Management to close campgrounds and recreation areas along 28 miles of the river, between the towns of Briceburg and Bagby, when water samples downstream from where the family died showed high levels of toxic algae.
Autopsies performed on the family and a dog necropsy were deemed inconclusive. Investigators have worked with toxicologists, environmental specialists and other experts.
The Associated Press contributed to this report.