Three US firefighters who died when their air tanker crashed while battling blazes in Australia have been identified.<br /><br />Captain Ian McBeth, 45, first officer Paul Clyde Hudson, 43, and flight engineer Rick A DeMorgan Jr, 44, were killed in New South Wales on Thursday.<br /><br />The cause of the C-130 Hercules crash is not yet known.<br /><br />New South Wales (NSW) Premier Gladys Berejiklian called it an "unbelievable loss" and offered a state memorial