(CNN) -- Australia's navy Monday opened two weeks of hearings into the World War II sinking of the cruiser Sydney II, an effort to formally close the book on the country's worst naval disaster. The gun turret of Sydney II was discovered with the rest of the vessel in March 2008. The ship's entire crew of 645 died when it was sunk by the German commerce raider Kormoran. About 15 relatives of the lost men attended Monday's opening session, said Cmdr. Jack Rush, the lawyer presenting the evidence gathered by investigators to a commission of inquiry led by a retired judge.
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The wreckage of Sydney II was found in March 2008 off Australia's western coast
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Delay in announcing the boat's loss in 1941 fueled various theories over the years
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Inquiry lawyer: Some proponents of theories will be allowed to present their case
The @placeholder ship inflicted "enormous damage" on the Sydney during a battle that is believed to have lasted about 35 minutes and left 70 percent of its crew dead or incapacitated, Rush said.
The @placeholder limped away and sank sometime between two to four and a half hours later, Rush said.
During the battle, however, the Kormoran was hit by an @placeholder shell that damaged its engines and set the vessel ablaze.