BRENNAN LINLSEY/Associated Press
In this March photo, retired U.S. Army Sgt. 1st Class Marshall Powell sits in his home in Crescent, Okla., looking at snapshots from his emotionally traumatic time serving as a nurse in northern Iraq in 2007, during one of the bloodiest years of the conflict. One night after bombing attack, Powell oversaw a hospital room designated for those with little chance of survival. There, amid the patients, he saw a wounded girl who reminded him of his niece back home. Maybe 6 years old, the Iraqi girl’s body was riddled with shrapnel, and her brown eyes implored him for help. Unable to save her, he gave her painkillers, and until recently could not forgive himself, or God, for her death.