Fifty-five-year-old American mountaineer Don Cash died after reaching the top of Mount Everest, the last in his goal to summit each continent’s tallest mountain. Cash, a Utah resident, had lost fingers to frostbite on previous trips but was reportedly unwavering in his determination to climb all seven mountains, his family said. Relatives believe that Cash had a heart attack while descending a portion of the trail on Everest. “He taught us that nothing was impossible,” his daughter, Brandalin Cash, told NBC affiliate KSL-TV.