LOS ANGELES — A popular and promising young mountaineer fell to his death on Yosemite's El Capitan on Wednesday, a tragedy that was reportedly live-streamed on social media. Balin Miller, 23, from Anchorage, Alaska, had already reached the top of the 3,000-foot granite wall — among the most famous and challenging rock climbs in the world — when a gear bag he was hauling behind him got stuck, ...