A young man from Mexico is dead after a group of border crossers got lost in the Arizona desert, the U.S. Border Patrol says.

The 18-year-old was among nine immigrants from the Mexican state of Oaxaca, according to the Border Patrol.

A member of the group called 911 Thursday, saying they were lost after a smuggler abandoned them. He said the 18-year-old had died after being in distress because of heat and insufficient water, the Border Patrol says.

A search began, and a Border Patrol plane spotted the group near Sells four hours later.

The cause of death is under investigation and the other immigrants were to be returned to Mexico, the agency said.

The Border Patrol isn’t releasing the dead man’s identity, spokesman Jeremy Copeland says.

Senior Editor, News, Arizona Daily Star, Tucson, Az.