PLEASANTON (KRON) — An 82-year-old Pleasanton man died Sunday at the Grand Canyon, according to National Park Service officials.

The Grand Canyon Regional Communications Center received a 911 call at about 12:10 p.m. Sunday from someone who said a man was unconscious near the Grand Canyon Visitor Center, according to the park service.

Bystanders tried to revive 82-year-old Khushalbhai Patel by administering CPR and using an automated external defibrillator, but he was pronounced dead when paramedics and park rangers arrived.

Patel died of natural causes, Coconino County Public Health Services District spokeswoman Trish Lees said.