() A woman has died after being struck by a falling tree branch while hiking in Yosemite National Park.

SFGATE reports that 29-year-old Angela Lin was hiking a trail through Tuolumne Grove with her boyfriend, David Hua, when the branch fell. Hua told the outlet that they heard a loud cracking only seconds before a large branch struck Lin.

Hua told SFGATE he called 911 and performed CPR until emergency services arrived, with responders telling him Lin most likely died instantly after being struck by the branch.

He cites a lack of communication from the park service following Lin’s death as the reason for sharing this story with the media and is calling for more to be done around trail safety and maintenance. While the Tuolumne County Sheriff’s Office has not issued a statement, a spokesperson for the park told the outlet that “the incident remains under investigation.”

According to the U.S. National Park Service, Tuolumne Grove is a popular trail that winds through a grove of giant sequoia trees. The trail has 500 feet of elevation changes and is considered strenuous.