The inquest into the fatal 1973 firebombing of the Whiskey Au Go Go nightclub in Brisbane is set to resume on Monday.
It follows a two-week sitting in June before coroner Terry Ryan.
Two drums of fuel were thrown into the downstairs foyer of the bustling nightclub in Brisbane's Fortitude Valley and set alight about 2am on March 8.
More than 60 patrons and staff tried frantically to escape as air conditioning vents acted as chimneys, pouring black smoke into the club.
Survivors smashed windows to scramble to neighbouring roofs, but not everyone made it out alive.
Fifteen people succumbed to deadly smoke, with autopsies confirming their death from carbon monoxide poisoning.
Two men - John Andrew Stuart and James Richard Finch - were convicted of murder over the crime and sentenced to life in prison.
Stuart died in 1979 and Finch - who had been due to give evidence in the inquest - died last year in the UK where he had been deported after serving 15 years.
Despite the two men being jailed for murder, the full extent of the circumstances causing the deaths had never been "satisfactorily established", an earlier hearing was told.
The new inquest was ordered after the firebombing was mentioned in a trial in which Vincent O'Dempsey and Garry Dubois were convicted over the deaths of Barbara McCulkin and her two daughters in January 1974.
That trial was told the killings may have been motivated over fears Ms McCulkin would try to implicate O'Dempsey in the firebombing.
O'Dempsey - who sat in the court during some testimony - was expected to be a key witness during the inquest and the coroner can compel him to answer questions.
Dubois was scheduled to give evidence, but was found dead in his cell at Maryborough Correctional Centre last year.
The Whiskey Au Go Go attack was Australia's worst mass murder until the 1996 Port Arthur massacre.
Australian Associated Press
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