An Australian visitor to Grand Canyon National Park possibly was struck and killed by a lightning bolt, though it will be up to a medical examiner to say for sure.

Park officials said the Grand Canyon Regional Communications Center received a call Sunday evening about an unidentified man who had possibly been hit by lightning while on the South Kaibab Trail. Paramedics were able to locate the unconscious hiker near Ooo-Aah Point approximately 1 mile down the trail. Medics were unable to resuscitate the man, 21-year-old Jonathan Crowden, of Alfredton, Australia, a park release said Monday.

An investigation was being conducted by the National Park Service in coordination with the Coconino County Medical Examiner.

Park rangers advise that lightning can strike 10 miles across the canyon. Grand Canyon visitors and residents should stay away from exposed points during storms and lightening activity. The safest place to be during a thunderstorm is inside a building or a vehicle with the windows closed. Avoid touching metal railings when lightning activity is nearby.

According to park staff, if you find yourself in an open area during a storm, you should squat or ball up to be as low as possible, without lying flat on the ground. Wrap your arms around your legs, keep your feet together, and if possible use a sleeping pad or other insulated object to sit on; avoid sitting on backpacks with metal frames.

Serious injuries and fatalities have occurred at Grand Canyon National Park in the past as a result of lightning strikes. Visitors to the park are reminded that if the sound of thunder follows a lightning flash within 30 seconds or less, they should seek shelter in a building or vehicle, or proceed to the nearest bus stop to get on a park shuttle.