Chris MacKenzie, of Hemet, also was killed in the fire fight, his uncle confirmed to NBC4. He was 30.
MacKenzie graduated Hemet High School in 2001 and joined the U.S. Forest Service.
When he was a teenager, MacKenzie lost 75 pounds, in part, so he could follow his father's footsteps as a firefighter.
"He really enjoyed it. He loved fighting fire," his mother Laurie Goralski said.
A second Hemet High School graduate was identified Monday afternoon as the third fire victim from Southern California.
William "Billy" Warneke, 25, is survived by his wife, his highschool sweetheart who is expecting their first child in December, his grandparents said.
Home videos show a young Warneke donning firefighting gear and climbing ladders into trees, pretending he was battling a blaze.
The father-to-be served in the Marines for four years, including on a deployment to Iraq, his grandparents said.
The Hemet Unified School District is mourning the loss of two of its graduates, Christopher MacKenzie and William Warneke who were both killed by a wildfire burning in Yarnell, Arizona, yesterday, June 30, 2013.
The firefighters were part of the Prescott Granite Mountain Hotshots, a 20-member elite firefighting crew.
MacKenzie attended Hemet High School and graduated in 2001.
And:
Warneke also attended Hemet High School and graduate in 2005.
The Hemet Unified School District would like to express its deepest gratitude and its condolences to all the families of these fallen heroes for their supreme sacrifice.