SACRAMENTO, Calif. (AP) — A family who died of heat exhaustion during a grueling summer hike in northern California sent one last desperate message asking for help, authorities said Thursday.

The Mariposa County Sheriff’s Office released information extracted from Jonathan Gerrish’s cell phone after months of working with an FBI forensic team.

A text message sent shortly before noon on August 15 to an unnamed person asked, “Can you help us” and added, “No water or excessive heating with baby,” reported the San Francisco Chronicle.

But the area had poor cell phone service and the text message never came through. Neither did five phone calls to various people, investigators said.

Ellen Chung, 31, her 45-year-old husband, their one-year-old daughter Aurelia “Miju” Chung-Gerrish, and their dog Oski were found dead on a hiking trail near the Merced River last August.

political cartoons

Their deaths baffled investigators. The case involved more than 30 law enforcement agencies who had thoroughly examined – and ruled out – causes such as murder, lightning, poisoning by algae-contaminated water, abandoned mines likely to emit poisonous gases, illegal drugs and suicide.

Last fall, investigators concluded the family died of extreme heat stroke. Temperatures that afternoon reached 109 degrees Fahrenheit (43 degrees Celsius) in the steep mountain terrain and the family ran out of water. A forest fire had burned away all shade canopy.

Authorities found the family two days later after relatives reported them missing. The family had traveled 6.4 miles (2.5 kilometers) with the baby in a backpack-style baby carrier. They were 1.6 miles (2.5 kilometers) from their car.

The family had an 85 ounce (2.5 liter) water tank with them that was empty.

The cell phone was found in Gerrish’s pocket. Shortly after noon, Gerrish and Chung attempted to call and text several times, according to the sheriff’s office.

Five phone calls — four of which were made in quick succession — went to multiple phone numbers, but the family did not call 911, the sheriff’s office said.

The first call was made at 12:09 p.m. Beginning at 12:35 p.m., the family made the final four calls in quick succession, investigators said.

However, none of the calls connected.

Copyright 2022 The Associated press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.