During World War II the Japanese attacked and held Kiska Island off the coast of Alaska for several weeks, but by the time any resistance forces arrived, the Japanese had already fled, however this did not stop blood being spilt.
Kiska Island is a small landmass among the Rat Islands in the trailing Alaskan horn. After the Battle of Dutch Harbor, the Japanese navy took on the small island encampment in 1942 and established what was one of the only cases of Japanese occupation on American soil in all of WWII. They also attempted to establish a presence on another nearby island but were quickly routed. However when allied forces (U.S. and Canadian) attempted to take back Kiska, they approached in an extremely dense fog and unknowingly fired on each other. Sadly the Japanese forces had actually abandoned Kiska just days before, learning from their previous defeat and using the same thick fog as cover. Before leaving the island, the Japanese left behind a number of booby traps which ended up inflating the body count above the already devastating friendly fire. In the end, almost 200 men were killed in the operation.
Today the occupation site has been marked as a national historic landmark, despite any formal monument. There are still some wrecks of Japanese ships and ruined piers, as well as other miscellaneous debris such as rusting artillery guns and bullet casings littering the abandoned island.