(KFYI News) – An off-duty Phoenix firefighter and a teenage boy died and another teen was injured after falling about 30 feet from a rock formation along the Echo Canyon Trail on Camelback Mountain Friday morning.

Phoenix Fire Department says 50-year-old Gary Johnstone died at an area hospital from injuries he suffered in the fall.  According to the fire department, Johnstone, along with his teenage son and two of his son's friends, were rock climbing and rappelling on a rock known as "Sugar Cube" when three of them fell.  Two of the three were unconscious when rescuers first arrived.

Johnstone's son was not hurt.  One of the other teens, identified as 15-year-old Trevor Crouse, had critical injuries and died late Friday night.  The other teen had only minor injuries.

Johnstone was a member of the Phoenix Fire Department's technical rescue team, meaning he would often go on such rescues.  He had been a firefighter for nearly 25 years, including about 15 years with Phoenix Fire, preceded by about ten years with Sun City Fire Department.

"Gary was well-loved," said deputy fire chief Shelly Jamison.  "He was at almost every event we hold as a member of the honor guard."

She says he also enjoyed being on the technical rescue team and rock climbing. "They embrace this.  They love climbing, they love outdoor activity.  So for Gary to be engaged in this type of activity on his day off probably isn't that unusual."

Johnstone leaves behind a wife and three sons.

The investigation into exactly what happened is still in progress.