Exposure to chemicals from a mine and the use of deadly weapons like a gun has been ruled out by the investigators as the cause of death of a Mariposa family who have gone hiking.

Found dead were 45-year-old Jonathan Gerrish; 30-year-old Ellen Chung; their 1-year-old kid and a family dog.

The Mariposa County Sheriff’s Office revealed further details on the timeline of events of the family, citing an account by a witness that the family left for the trail on the morning of Aug. 15.

A total of 8.5-mile loop was hiked by the family, investigators said. Among the trails they took was the 5-mile steep southern open trail, which exposed them to temperatures ranging 103 to 109.

“We know the family and friends of John and Ellen are desperate for answers, our team of detectives are working round the clock,” a statement of Sheriff Jeremy Briese said. “Cases like this require us to be methodical and thorough while also reaching out to every resource we can find to help us bring those answers to them as quickly as we can.”

Toxicology reports and cell phone data on the case are still unreleased.

Water samples from the areas as well as what the family brought with them are being investigated as authorities have not excluded water toxicity as the cause of death.

For the first time on Thursday, investigators said Gerrish had looked through a phone application about a Hites Cove hike a day before they headed to the trail.

A witness said the family went to the trailhead in their truck at 7:45 a.m. on Aug. 15. The following day, they were reported missing.

Their truck was found by the Mariposa County sheriff’s deputy on Aug. 16 at the end of Hites Cove Road.

The family was discovered lifeless in the trail leading back to their vehicle at 11:00 a.m. In a seated position, Gerrish’s dead body was along with her daughter and the dog while Chung was found up the path, San Francisco Chronicle reported.

According to investigators, the family took the majority of the loop before dying on a steep part located around 1.5 miles beneath their car’s location.