WATCH: One wrong step sends him toward the roaring river below. Chinese slackline athlete Shi Hailin takes on a 100-meter upstream crossing above Tiger Leaping Gorge in southwest China, balancing on a line just 2.5 centimeters wide. Powerful canyon winds whip the slackline from side to side as Shi spreads his arms, bends his knees, and pauses to regain control above the rushing Jinsha River. The gorge drops more than 3,000 meters in elevation, creating strong, unpredictable winds that make an already extreme challenge even tougher. ▻