For Chu Yeon-hee, 40, one day in April 2008 changed everything. At the time, Chu was in his third year as a noncommissioned officer (NCO) working as an aircraft mechanic with an Army aviation unit. While moving equipment, Chu fell from the fourth floor of a building. Rushed to a civilian hospital, Chu underwent an eight-hour operation in which surgeons inserted eight metal screws into his first through fourth lumbar vertebrae. The damaged spinal nerves never recovered. No matter how hard Chu concentrated, not even a single toe would move. Doctors diagnosed him with incomplete paralysis of the lower body caused by damage to the cauda equina — the bundle of nerves at the base of the spinal cord resembling a horse's tail. A military career was no longer possible. Chu had fulfilled a family tradition by becoming the third consecutive generation to serve as an NCO in 2006. Proud of that legacy, he had begun training to become an Army helicopter pilot and warrant officer when the accident abruptly ended the first chapter of life. Although despair overwhelmed the 22-year-old, Chu eventually f