After protecting the transports during the original landings, the minelayer proceeded in mid-afternoon to a fire support sector southeast of Mount Suribachi. At 17:37 — only from the nearest beach—she began delivering call fire under the direction of a shore fire control party. She poured in 5-inch gunfire on enemy machinegun and mortar nests on the northeast base of the formidable mountain. Shortly before sunset, she shifted her fire to positions in the caves near the base of Mount Suribachi. Japanese machinegunners on shore fired on the ship but did no damage. That evening, Thomas E. Fraser moved to a position southwest of Mount Suribachi and delivered call fire and illumination rounds throughout the night. Her star shells made it possible for Marine mortars to foil a Japanese attempt to infiltrate an American position via the sea. In the days that followed, Thomas E. Fraser alternated anchorage screening duties with fire support missions to assist Marines fighting ashore. Early on the morning of 21 February, as Thomas E. Fraser was firing on the northeast base of Mount Suribachi, a near miss by a large shell of undetermined origin caused a hole in her starboard side just below the main deck. Nevertheless, she continued firing on targets of opportunity until late in the afternoon when she returned to anchorage patrol.