During the WWII, the Americans invaded Okinawa via Operation Iceberg to use it as a base for air operations on their planned invasion of mainland Japan. The Battle of Okinawa lasted for 82 days and was known to be one of the bloodiest in the Pacific. Dubbed as “tetsu no ame” (rain of steel), the battle was so ferocious due to the intensity of kamikaze attacks from the Japanese defenders, and to the sheer numbers of Allied ships and armored vehicles that assaulted the island.