The President of the United States of America takes pride in presenting the Silver Star (Posthumously) to Captain William D. O’Brien (MCSN: 0-4057), United States Marine Corps Reserve, for conspicuous gallantry and intrepidity as Reef Transfer Officer attached to the THIRD Marine Division, Fleet Marine Force, during action against enemy Japanese forces on Asan Beach, Guam, Mariana Islands Group, on 22 July 1944. When a mortar shell exploded near his foxhole killing one man and wounding two others during the landing and occupation of the strongly defended beachhead, Captain O’Brien immediately left his shelter and skillfully administered first to the wounded and, fearing that the lack of professional medical care might prove fatal to the casualties, defied the withering mortar fire to search for a hospital corpsman. Finding a corpsman after advancing fifty yards along the fire-swept beach, he fearlessly directed him to the casualties and, when emergency treatment had been given, kept vigil until the wounded were evacuated at dawn. By his cool courage, resolute fortitude and valiant devotion to duty in the face of grave peril, Captain O’Brien upheld the highest traditions of the United States Naval Service.