A man died and at least two more people were rescued after the group ran out of water while hiking in the mountains north of Malibu on Monday afternoon, officials said.
The rescue operation began around 4 p.m. after the Los Angeles County Sheriff's Department's Malibu-Lost Hills Station received a 911 call reporting the hikers were in trouble, sheriff's Lt. Pauline Panis said.
The caller reported that one person in the group had died from apparent heat exhaustion, the lieutenant said.
A search and rescue team, as well as a sheriff's department helicopter, were sent after the hikers, officials said.
Authorities found them and confirmed that one of the hikers, a man estimated to be in his 60s, was dead, Los Angeles County Fire Department officials said.
At least two additional hikers also displayed signs of heat-related illness, officials said. They were flown to safety but declined to be taken to hospitals.
The investigation was ongoing.