At the time of World War II, Kiska Island was occupied by twelve men of a United States Navy weather station, two of whom were not present during the Japanese invasion. On 6-7 June, 1942, in actions designed to roughly coordinate with their attack on Midway Island, Japanese forces occupied both Kiska and Attu Islands against no opposition. On Kiska they built an airfield, a series of coastal and anti-aircraft defenses, a submarine base, seaplane base, and quarters for troops.
The picture [below] shows the Japanese midget submarine base on Kiska Island under inspection by U.S. and Canadian troops in September, 1943. The submarines had been destroyed by the Japanese upon evacuating the island. And the site as it appears today.