PURPLE HAZE U.S. Army Sgt. Spencer Harmon, left, and Pvt. Nathan Nicholson run into smoke for concealment during a simulated training exercise lane at the Joint Readiness Training Center, Fort Polk, La., June 18, 2009. The exercise is part of pre-deployment training with the 2nd Infantry Division's 4th Brigade Combat Team. All the soldiers are assigned to Company B, 4th Battalion, 9th Infantry Regiment. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 712679-Q-YHV88-210.jpg Photo Gallery