Back in August 2015, two high school students were asleep in a tent in the Upper Pines Campground when an oak limb fell, killing them both. And in 2012, a concessions worker was killed when a tree fell on his tent cabin during a windstorm.

A 29-year-old Google software engineer was killed hiking in Yosemite National Park when a branch from a giant sequoia tree fell and hit her on the head. Angela Lin, an engineer at Salesforce and then Google, was hiking on July 19 with her boyfriend and two friends through Tuolumne Grove, a paved trail lined with massive sequoias.

The trails of Tuolumne Grove, a popular site in Yosemite National Park, wind through forests of pine and giant sequoias, the largest trees on earth. On July 19, after hiking about a mile into the grove, Angela Lin, 29, and her friends heard a snapping sound above them.