"On May 11, 1943, in a mission code-named Operation Landgrab, the U.S. military landed 11,000 infantry on the north and south ends of Attu. Because the Japanese commander on Attu, Colonel Yasuyo Yamasaki (1891–1943), had moved his greatly outnumbered troops inland to the island’s high ground, the U.S. soldiers at first encountered only light resistance. Still, the island’s harsh weather and rugged terrain proved to be formidable allies for the Japanese.
Attu is a barren, mainly treeless volcanic island with weather that can change quickly from still winds and light fog to raging 100-mile-an-hour gusts and driving rain. Having occupied the island for almost a year, Japanese troops had acclimated to its difficult conditions. However, American soldiers initially found themselves ill-equipped and ill-prepared to navigate the difficult terrain and withstand its snow, fog, rain and mud while inspecting every foxhole and hollow in search of their Japanese enemy.
Because U.S. Army planners had expected the battle to last only a few days and had not anticipated how grueling the conditions would be, American soldiers conducted operations in substandard clothing with inadequate gear. Exposure to the drenching rains and freezing cold inflicted more casualties than enemy fire as hundreds of U.S. troops suffered frostbite, trench foot and gangrene. Equipment failures and food shortages added to their misery as they crisscrossed the barren island fighting mostly small but fierce engagements."