GRAND CANYON NATIONAL PARK, Ariz. (AP) -- Authorities say a 73-year-old man is dead after collapsing while hiking in Grand Canyon National Park. Park officials didn't immediately release the name of the man or his hometown Friday. Officials say they received a 911 call around 1 p.m. Thursday about a deceased man in the vicinity of Ribbon Falls near the North Kaibab Trail. Park ranger medics responded by helicopter. Officials say the man was day hiking from Phantom Ranch to Ribbon Falls with several companions. After he collapsed, bystanders performed CPR while another park visitor hiked to a place on the trail where limited cell service is available. The man was pronounced dead after medics arrived on the scene. The body was transported to the Coconino County Medical Examiner's Office to determine the cause of death.