developments on the islands. Admiral Isoroku Yamamoto provided the Japanese Northern Area Fleet, commanded by Vice-Admiral Boshiro Hosogaya, with a force of two non-fleet aircraft carriers, five cruisers, twelve destroyers, six submarines, and four troop transports, along with supporting auxiliary ships. With that force, Hosogaya was first to launch an air attack against Dutch Harbor, then follow with an amphibious attack upon the island of Adak, to the west. Hosogaya was instructed to destroy whatever American forces and facilities were found on Adak, but the Japanese did not know the island was undefended. Hosogaya's troops were to return to their ships and become a reserve for two additional landings: the first on Kiska, west of Adak, the other on the Aleutians' westernmost island, Attu, west from Kiska. Because the US Naval Intelligence had broken the Japanese naval codes, Admiral Chester Nimitz had learned by May 21 of Yamamoto's plans, including the Aleutian invasion, the strength of both Yamamoto's and Hosogaya's fleets, and Hosogaya's plan to start the fight on June 1 or shortly thereafter. As of June 1, 1942, the US military strength in Alaska stood at 45,000 men, with about 13,000 at Cold Bay (Fort Randall) on the tip of the Alaskan Peninsula and at two Aleutian bases: the naval facility at Dutch Harbor on Unalaska Island, west of Cold Bay, and the recently built Fort Glenn Army Airfield west of the naval station on Umnak Island. Army strength, less air force personnel, at those three bases totaled no more than 2,300, composed mainly of infantry, field and antiaircraft artillery troops, and a large construction engineer contingent, which was used in the construction of bases. The Army Air Force's Eleventh Air Force consisted of 10 B-17 Flying Fortress heavy bombers and 34 B-18 Bolo medium bombers at Elmendorf Airfield, and 95 P-40 Warhawk fighters divided between Fort Randall AAF at Cold Bay and Fort Glenn AAF on Umnak. The naval commander was Rear Admiral Robert A. Theobald, commanding Task Force 8 afloat, who as Commander North Pacific Force (ComNorPac) reported to Admiral Nimitz in Hawaii. Task Force 8 consisted of five cruisers, thirteen destroyers, three tankers, six submarines, as well as naval aviation elements of Fleet Air Wing Four. When the first signs of a possible Japanese attack on the Aleutians were known, the Eleventh Air Force was ordered to send out reconnaissance aircraft to locate the Japanese fleet