Noted climber falls to his death at Yosemite National Park's El Capitan rock formation

Balin Miller, a noted mountain and rock climber, fell to his death this week at the El Capitan rock formation in California's Yosemite National Park, his mother said.

The 23-year-old's death was reported on Wednesday, mother Jeanine Girard-Moorman told NBC affiliate KTUU in Anchorage, Alaska, Miller's home state.

“My whole world just fell apart, and it’s tough,” she told the station. “There’s no greater pain than losing your child in such a horrific way.”

Details of how he died are not immediately clear.

Dylan Miller told The Associated Press that his brother was climbing a 2,400-foot route along the El Capitan cliffside alone with the help of a rope when he likely rappelled off the end of his rope.

Climbing photographer Tom Evans wrote on Facebook that he witnessed the fall, which he said happened along a route called Sea of Dreams.

Evans wrote that Balin Miller had already completed the Sea of Dreams climb when he was seen rappelling off the end of his rope during an attempt to clear a stuck bag.

"His rope didn't reach the bags location by many feet, but he seemed unaware of that fact," Evans wrote. "On the way down he rappelled off the end of the rope."

Girard-Moorman compared the mistake to forgetting to wear a seatbelt only one time among countless drives.

"It was simple, like you forget to put your seatbelt on," she told KTUU. "And that is the day you needed it."

She said her son knew the risks, "and he just did it anyway.”

The National Park Service did not immediately respond to a request for information. In a statement cited by The Associated Press, it said its rangers and emergency personnel responded quickly, and that the incident is under investigation.

National parks are generally open amid the government shutdown, which began Wednesday, but with limited services.

Balin Miller’s death follows two others at the park this year. Hiker Angela Lin, 29, was killed when she was struck by a falling tree branch, authorities said, according to NBC affiliate KSEE of Fresno, California. And an 18-year-old from Texas died while climbing without a rope on a different formation, The Associated Press reported.

Miller was gaining notoriety for his solo climbs. Earlier this year, he claimed on his Instagram page that he made a solo ascent of the Slovak Direct route of Alaska's Mt. McKinley, a historic first.

"He was an incredible athlete," his mother told KTUU.