A man died over the weekend while hiking at the Grand Canyon, according to the National Park Service.

The National Park Service says at about 2 p.m. Sunday, authorities were alerted to an unresponsive hiker on the Bright Angel Trail, about 100 feet below the trailhead. Bystanders performed CPR as medical personnel responded from the rim. All attempts to treat the individual were unsuccessful and the man was pronounced deceased.

NPS says the man was in his 50s and was from San Angelo, Texas. He was reportedly attempting to return to the rim after an overnight stay at the Havasupai Gardens. His identity hasn’t been released.

Details on what caused the man’s death have not been released.

An investigation into the death is being conducted by the NPS and the Coconino County Medical Examiner.