(CNN)“Jump.” In midair, he maneuvered himself so that his legs would hit the water first. Hines fell 220 feet at about 75 miles per hour. The impact from a fall like that is similar to hitting concrete. The contact shattered two of his vertebrae, and doctors later told him that he was only 2 millimeters away from severing his spine. In excruciating pain, Hines struggled to the surface and felt a creature nudging at him.