On Tuesday, rangers were notified of CPR in progress about a half mile below the South Kaibab Trailhead.
National Park Service EMS personnel responded and found bystanders conducting CPR on 60-year-old William Smith of Oswego, Ill.
Smith had been hiking out of the canyon after completing a day hike to Ooh Ahh Point, about one mile down the South Kaibab Trail.
Despite attempts to resuscitate Smith, rangers say he passed away at the scene.
National Park Service and the Coconino County Medical Examiner are now investigating his death. No additional details are available at this time.
Grand Canyon National Park rangers are advising hikers to postpone challenging hikes or trying new activities while first responders continue to focus on other incidents.
This is the second death in a week at Grand Canyon National Park.
Sunday, 53-year-old Michelle Meder of Ohio was backpacking in the park when she died. Rangers believe her death is heat-related.
National Park officials are warning recreators of the extreme heat – and related dangers – that can sneak up on unsuspecting visitors.