On this day in 2013, 34-year-old aerialist Nik Wallenda becomes the first person to walk a high wire across the Little Colorado River Gorge near Grand Canyon National Park in Arizona. Wallenda wasn’t wearing a safety harness as he made the quarter-mile traverse on a 2-inch-thick steel cable some 1,500 feet above the gorge. In June of the previous year, Wallenda, a member of the famous Flying Wallendas family of circus performers, became the first person to walk a tightrope over Niagara Falls.