On 30 May 1942, "I-22", "I-24", and "I-27" arrived off Sydney. Between 17:21 and 17:40 on 31 May, each launched her midget submarine to begin what became known as the Attack on Sydney Harbour. "I-22"′s midget, "M21", reached the harbor, where the patrol boat tried to ram her, then dropped depth charges. "M21" survived "Yandra"′s attack, but when the patrol vessel attacked her off Taylors Bay and disabled her, "M21"′s two-man crew shot themselves to death. Allied forces later found "M21" on the harbor bottom with her motor still running. "I-24"′s and "I-27"′s midget submarines also were lost.