One of the Truk wrecks not a casualty of Task Force 58 fast carrier raid Operation Hailstone, in February 1944, is the large Japanese submarine I-169. She was present in Truk Lagoon loading stores on 4 April 1944 when an alarm for an imminent US air raid was issued. I-169 dived before all her deck hatches were closed. Her control room flooded and she sank to the bottom – with crew still alive inside sealed compartments. Despite salvage attempts over the coming days, they would all perish.