A wildland firefighter collapsed and died Sunday afternoon while working near Mayhill, New Mexico.
Fellow crew members administered CPR on Daniel Davidson, 26, but they were unable to revive him, authorities said.
A Life Flight helicopter crew also responded, but Davidson was pronounced dead at the scene.
A U.S. Army veteran who had served two tours in Afghanistan with the 10th Mountain Infantry Division, Davidson was assigned a crew member of Engine 621 on the Sacramento Ranger District of the Lincoln National Forest.
Details of the work project he was involved in when he collapsed have not been released yet.
Funeral arrangements are pending.