A non-verbal teenager's affinity for rocks has proved to be life-saving after the sound of him banging them together alerted a rescue team to his location.
The teen ran into nearby trees and went missing after going on a hike with mother and sister in Los Angeles, California.
Members of the search and rescue team said they heard a "piercing sound" through the thick bushes of the Crescenta Valley Park, where they were searching for the developmentally-delayed teen.
After hearing the sound repeatedly, Sheriff Steve Goldsworthy said he he had a hunch to follow the unusual clinking noise through. as reported by NBC news.
Sheriff Goldsworthy, a member of the Los Angeles County Sheriff's Department Montrose Search-and-Rescue Team said: "We were hollering down in this canyon, and I heard something come back.
"It sounded like somebody taking two rocks and putting them together. I could hear the rocks hit, and a slight echo. I could hear that three different times."
In a post on Facebook discussing the incident, the team wrote: "Our team member went down the mountainside and made contact with the missing person.
"Recognizing the sensitivity of the situation, he worked to build a rapport with the teenager.
"After gaining the trust of the missing person, he led him up the mountain to safety. Once at the top, he was treated by paramedics and released to his family."
The team found the 16-year-old north of the park with the help of aerial footage.
He adds: "I found him basically sitting under an oak tree, probably three miles from where he was last seen with his mum. “He will go out of his way to kick a rock, pick up a rock, throw a rock,"
"Those were, like, his favorite things, so I picked up the rock and threw it down the gully, and he looked at me, and he ended up giving me a fist bump."
