A 34-year-old Indiana man who died after being struck in the head by a large rock near Waimoku Falls has been identified as Greg Miller, according to Lt. Gregg Okamoto of the Maui County Police Department.

The exact cause of death has yet to be determined.

Just after 6:20 p.m. Saturday, firefighters responded to a call of a man later identified as Miller of Fort Wayne who was struck by a falling rock, described to be the size of a watermelon, near the base of a waterfall at Oheo Gulch of the Kapahulu district of Haleakala National Park.

Miller along with a 30-year-old Indiana woman and two friends from Wailuku were in a Pipiwai Stream tributary — about a 15-minute off-trail hike from Waimoku Falls — when Miller was struck by the rock, according to news releases by the park and the Maui Fire Department.

Firefighters arrived and encountered two of his friends while hiking up Pipiwai Trail. They informed firefighters that he had suffered head trauma and was not breathing. He also did not have a pulse despite efforts to resuscitate him.

Rocks had continued to fall in the area after the initial large rock struck Miller.

Due to unsafe conditions, firefighters left the site Saturday night and returned Sunday morning when they located him with “massive head trauma” at the bottom of a 200-foot waterfall.

The fire department’s Air 1 helicopter airlifted Miller to a landing zone near the national park’s visitor center.