Three elderly hikers died in apparent heat-related deaths while traversing the Grand Canyon’s inner trails as temperatures spiked above 100 degrees. 

Rangers and emergency personnel responded to two separate heat-related incidents on June 12 and June 16, according to the National Park Service.  

“In both cases, the deceased hikers were hiking trails in the Inner Canyon, where temperatures can exceed 109 F in the shade during midday hours,” the statement said.

Emergency responders arrived to find the hikers already deceased on the trails. A 72-year-old man was found dead June 12 on the South Kaibab Trail due to heat-related symptoms, park officials said. A 67-year old man and a 68-year-old woman were found dead on the North Kaibab Trail on June 16, park officials said. 

An investigation into their causes of death is still ongoing, although they appear to be heat-related.

The hikers were transported to Coconino County Medical Examiner’s office.

Earlier this month, a teen died from apparent heat-related causes after attempting a round-trip day hike from the South Rim of the canyon to the Colorado River. Emergency responders launched a helicopter rescue operation. Searchers ultimately found the teen in a remote area about 30 feet below the trail.

An elderly man died last year while attempting to reach the Colorado River for an overnight stay at Phantom Ranch, a popular camping site, park officials said.