In this March 23, 2017 photo, American medical volunteers attend to a civilian casualty of the battle to retake Mosul from Islamic State militants, at the the Samaritan’s Purse field hospital, in Bartella, Iraq. Situated on the outskirts of Mosul, the state-of-the-art field clinic was set up last December by Samaritan’s Purse, a Christian aid organization based in Boone, North Carolina. Its volunteer doctors receive those with the gravest injuries from the field clinics inside or at the very edge of Mosul, where casualties are initially treated. (AP Photo/Tomislav Skaro)