Authorities say a man from Switzerland has died while hiking Camelback Mountain in Phoenix.
The name of the 26-year-old man and his hometown weren't immediately available.
Phoenix Fire Department officials say the man had been hiking Friday afternoon with three friends before he got separated from the group.
They say he was heard yelling for help by employees of the Phoenician Resort, who went to meet him.
The man was nearly down the trail and on resort property when employees say he began acting erratically and then stopped breathing.
Bystanders performed CPR on the man until fire crews could take over medical treatment.
Crews continued performing CPR on the man on the way to a Phoenix hospital, where he was pronounced dead.