One of Australia's greatest mysteries has finally been solved thanks to advances in DNA technology, with the 'Unknown Sailor' finally identified exactly 80 years after he died. Thomas Welsby Clark was just 21 years old and an able seaman on HMAS Sydney when it was sunk on November 19, 1941, about 200km off Western Australia. He had trained as an accountant in Brisbane, then served in the army before finding a berth on HMAS Sydney. His remains washed up on Christmas Island, 2,600km north-west of Perth, 11 weeks after the HMAS Sydney was lost, and it was all that was...