FORWARD OPERATING BASE DELHI, Afghanistan — The sounds from a controlled flurry of medical activity drifted through a narrow hallway packed with patients, stretchers and U.S. Navy corpsmen, funneling their calm conversations and unbreakable focus into the buzzing aid station.

Faced with a mass casualty situation following an attack by a suicide bomber in southern Helmand province’s Garmsir district, corpsmen with 3rd Battalion, 3rd Marine Regiment treated eight wounded Afghan National Policemen here, April 19, 2012.