Fegan spent three months with training on Hawaii and embarked with his regiment for Marianas Islands in mid-May 1944. He took part in the landing on Saipan and led his battery ashore on June 15, 1944. Fegan boldly exposed himself to heavy and sustained enemy shelling to lead his battery into position and commence firing. By nightfall, with his entire emplacement under intense bombardment by shells and small-arms fire, he gallantly moved from one gun crew to another, encouraging and rallying his men and those in adjacent posts.