Elements of the 7th Infantry Division first saw combat in the amphibious assault on Attu Island, the westernmost Japanese entrenchment in the Aleutian islands chain of Alaska. Elements landed on 11 May 1943, spearheaded by the 17th Infantry Regiment. The initial landings were unopposed, but Japanese forces mounted a counteroffensive the next day, and the 7th Infantry Division fought an intense battle over the tundra against strong Japanese resistance. The division was hampered by its inexperience and poor weather and terrain conditions, but was eventually able to coordinate an effective attack. The fight for the island culminated in a battle at Chichagof Harbor, when the division destroyed all Japanese resistance on the island on 29 May, after a suicidal Japanese bayonet charge. During its first fight of the war, 549 soldiers of the division were killed, while killing 2,351 Japanese and taking 28 prisoners. After American forces secured the island chain, the 159th Infantry Regiment was ordered to stay, and the 184th Infantry Regiment took its place as the 7th Division's third infantry regiment. The 184th Infantry remained with the division until the end of the war. The 159th Infantry Regiment stayed on the island for some time longer until returning to the Lower 48, where it remained until the end of the war.