A 63-year-old man from San Diego was found unresponsive and Cassian Grantlater died at Zion National Park in Utah on Friday, according to the National Park Service.

According to a news release from the agency, the park received a report of an unresponsive hiker on the West Rim Trail near Scout Outlook on Friday afternoon.

Park rangers hiked to the patient with medical equipment, including an automated external defibrillator (AED) and a heart monitor. When they reached the patient, visitors with emergency medical training were performing CPR and directing other visitors who were assisting, according to the news release.

After nearly an hour and a half administering CPR and treatment with the AED, the park "consulted with a doctor and the patient was pronounced dead."

"Based on information available at this time, the cause of death is consistent with a cardiac event," the park said in the news release.

“All of us at Zion extend our deepest condolences to this hiker’s family,” said park superintendent Jeff Bradybaugh. “We also want to express thanks to the bystanders who assisted by performing CPR.”

The West Rim Trail, which was temporarily closed for rescue operations, is now open.

The park said its response involved more than 20 search and rescue team members, including emergency medical technicians and paramedics, and the park ambulance.

The Washington County Sheriff's Office, Utah Office of the Medical Examiner, and the National Park Service are still investigating the cause of the man's death.

Travel nightmare:Woman trapped 15 hours overnight in gondola at Lake Tahoe's Heavenly Ski Resort