A new investigative report revealed that a couple who died in their hike under a 109-degree heat on a California trail struggled to save their 1-year-old child before their death, SFGATE reported.

Jonathan Gerrish, 45, and his wife Ellen Chung, 31, were found dead on Aug. 17 in the Sierra National Forest along with their daughter, Miju, and family dog, Oksi.

Their bodies were retrieved along the Savage Lundy Trail in the Sierra National forest.

Their probable cause of death was hyperthermia and possible dehydration, Mariposa County Sheriff Jeremy Briese said in October.

The San Francisco Chronicle on Friday has secured a new report of 77 pages containing the perception of the last hours of the family.

The couple, as investigators believe, tried to look for medical assistance for their daughter before they succumbed to heat.

The report said that the family started their hike before 8 in the morning on aug. 15. By that time, the temperatures were still around 70 degrees.

The heat increased to more than 100 degrees within hours. No shade was available in the area, making the ground very hot.

The family’s disappearance was first reported by their babysitter around 11 in the evening on Aug. 16.

The couple, their daughter, and their family dog were located less than a day later.

Officials have warned against hiking the trail during hot months, the same trail the family had completed about four-fifths of their hike.

According to the investigative report, Chung was found a distance ahead of her husband, prompting authorities to believe she was seeking out help when she collapsed.

His husband appeared to have tried to cool down with the kid who is believed to have already struggled from the heat.

Investigators said their dog also had a hard time because of the heat.

The family only had about 85 ounces of water with them.

“Our hearts will never forget the beautiful lives of Jonathan, Ellen, Miju, and, of course, Oski,” the bereaved family said in August. “They will remain with us wherever we go.”