The family that was found deceased on a Northern California hiking trail died of heat and dehydration, officials announced Thursday.
During a press conference, Mariposa County Sheriff Jeremy Briese cited "hyperthermia and probable dehydration" as the cause of death of John Gerrish, Ellen Chung and their 1-year-old daughter Miju.
The family was reported missing after heading off for a hike in an area near Devil's Gulch in the Sierra National Forest in August. Their bodies were discovered on Aug. 17 along with the body of their dog, according to video footage of the press conference shared by The Fresno Bee.
The location where the bodies were found was originally treated as a hazmat scene because the cause of the deaths could not be immediately determined. At the time of their deaths, the Sierra National Forest had toxic algae bloom warnings in effect.
"Heat-related deaths are extremely difficult to investigate," Briese said.
He added that an empty 85-ounce water bladder backpack was found on the family, and no other water containers or water filtration systems were discovered, according to NBC News.
The section of the trail the family was found on is exposed to constant sunlight and has little shade, Briese noted. Temperatures in the area at the estimated time of their death were between 107 and 109 degrees.
The cause of death for Oski, an 8-year-old Aussie/Akita mix, has not yet been determined, but investigators believe it was also due to exposure to the elements.
"This is a tragic incident, tragic situation," Briese said.