 Roos made the walk in just under three hours, all while battling high winds and blazing hot temps. He did so by walking on a slack line, which hangs looser than a tightrope. At its highest point, the line hovered more than 800 feet above the water. Now, the walk was not perfect. Just before the finish, Roos lost his balance and fell from the line, but thankfully he was caught and saved by a safety belt attached to the wire.