John Patterson, a wounded warrior and medically retired Marine, was injured when a bomb went off as he entered a building during a combat patrol Jan. 23, 2011. The blast severed his left leg below the knee. Patterson, a native of Columbia, Md., now works as an intern at Program Executive Officer Land Systems through the Wounded Warrior Intern Program, part of the Naval Acquisition Development Program. - John Patterson, a wounded warrior and medically retired Marine, was injured when a bomb went off as he entered a building during a combat patrol Jan. 23, 2011. The blast severed his left leg below the knee. Patterson, a native of Columbia, Md., now works as an intern at Program Executive Officer Land Systems through the Wounded Warrior Intern Program, part of the Naval Acquisition Development Program.