The Americans’ ‘Operation Iceberg’ to take Okinawa was the largest amphibious assault of the Pacific War, and the ensuing 82-day ‘Typhoon of Steel’ was its bloodiest battle, costing on both sides over 240,000 dead, more than half being civilians. With American and British aircraft carriers dominant at sea, and having secured the nearby Kerama Islands, on 1 April the American 14th and 3rd Corps landed on Okinawa’s western Hagushi beaches relatively unopposed. They rapidly captured Kadena and Yomitan airfields and by 13 April had gained control of the northern half of the island, cornering the Japanese on the Motobu Peninsula. The US 7th and 97th Divisions drove south and became engaged in heavy fighting near Shuri, a prelude to major battles for Kakazu Ridge and Conical Hill, captured on 13 May. From the coast, the 1st and 6th Marine Divisions took Sugar Loaf Hill and Shuri Castle, trapping the Japanese, who began a tactical retreat southwards to the Kiyan and Oroku Peninsulas, where on 13 June there was a mass suicide of Japanese sailors. Resistance largely ceased by 21 June, but Okinawa did not surrender officially until 7 September.