An Australian coroner has criticised mining company Beaconsfield Gold, but found it was not directly responsible for the 2006 disaster in which miner Larry Knight was killed.
Tasmanian coroner Rod Chandle handed down his findings in Launceston on Thursday after a lengthy inquest last year.
Mr Chandler ruled that the rockfall which killed Larry Knight and trapped Todd Russell and Brant Webb on 25 April 2006 could not have been foreseen.
Mr Chandler told the court that a seismic event six months before the tragedy was a warning that more rock falls were likely and required a thorough risk assessment by the mining company, Beaconsfield Gold, which did not happen.
The coroner also found that the resourcing of Tasmanian mine inspectors was inadequate and Tasmania's mining laws require urgent change, the ABC website reports.
Larry Knight's brother, Shane, said the findings have let the mine's management off the hook.
"I am a bit disappointed in the findings today. I know it was a very complex matter," Mr Knight said.
"I believe Larry and Brant and Todd should never have been sent into 925 level, knowing the conditions as they were," he said.
Beaconsfield Gold said it was pleased with the Coroner's findings but disappointed with his comments about the risk assessment.
Outside court, Beaconsfield mine manager Richard Holder said the company strongly disagrees with the Coroner's finding that the mine did not assess its ground support or change its mining method before the tragedy.