In May, 2018 USFWS wildlife technician Amber Kornack was collecting bear hair samples in Montana and despite following recommendations to make noise with whistles and hand claps to alert bears, she ended up walking to within 12 feet of a male grizzly bear. Once the bear noticed her, it attacked, and bit her head causing a skull fracture. She managed to drive it away with bear spray and ended up walking 2 miles with this severe injury in order to get back to her vehicle. The bear was relocated in 2019 after causing problems in a populated area.
Sources: Minneapolis Star-Tribune, October 29, 2019, NBCMontana.com