When Australia pulled its combat forces from Vietnam in late 1971, the bodies of six remained behind: four soldiers lost in three separate clashes plus the two airmen. A search mounted by a veterans’ organization discovered the remains of two soldiers in 2007, prodding the Australian government to step up its efforts. The other soldiers’ bodies were then located, one later in that year and the other in 2008. That left only the remains of the two airmen, always regarded as the most difficult to retrieve because there was little idea of where their jet crashed. But in April, a search conducted by the Australian army history unit found wreckage in thick jungle on a hillside in remote Quang Nam province, near the Laos border. The two men, both aged 24, were the sole crew of a bomber that crashed after a mission on Nov. 3, 1970. The United States still has nearly 1,800 servicemen unaccounted for throughout Southeast Asia, some 1,335 in Vietnam alone.