At least four hikers have died in the Grand Canyon this month due to suspected heat-related illness, according to the National Park Service.

The deaths occurred during separate incidents in mid-June, including a 72-year-old man on the South Kaibab Trail and a 67-year-old man and 68-year-old woman on the North Kaibab Trail, where temperatures can exceed 109°F.

Despite rapid response efforts and helicopter support, all three individuals were found dead when rescuers arrived.

Earlier in the month, an 18-year-old also died after suffering heat-related symptoms on the Bright Angel Trail during a day hike, Fox News has reported.

Park officials said all cases remain under investigation in coordination with the Coconino County Medical Examiner.