AFTER the electrocution of 25-year-old Brisbane man Matthew Fuller in October 2009, then Environment Minister Peter Garrett could have banned foil insulation, suspended the program or forced installers to cut power before installing ceiling insulation.
Instead he banned the use of metal staples - a decision that lawyers for the victims believe did little to help prevent the death toll rising to four.
Former Prime Minister Kevin Rudd was expected to face the commission on Wednesday afternoon.
The $20 million Royal Commission is examining the Rudd Government's botched home insulation program that ran throughout 2009 and early 2010.
He faced a crowd of lawyers interrogating him on why more was not done after the death of Mr Fuller to prevent further fatalities.
Mr Garrett said Mr Fuller's death "gutted" him.
He sought to blame the government's response on a lack of information passed on by staffers.
Mr Garrett was repeatedly asked by a variety of barristers why he himself did not consider how best to reduce the risk of injury and death.
He said his role as minister meant he had many responsibilities and relied on advice.
He faced pointed questions from Elizabeth Wilson QC who was representing the family of Rockhampton victim Rueben Barnes, 16, who was killed a month after Mr Fuller.
Aside from the four killed, the program is blamed for hundreds of house fires.
The commission heard during cross-examination how the government could have banned the use of foil insulation after the death, which had been known to cause electric shocks.
Installers could have been forced to switch off power to homes needing insulation by making it a condition for installers wanting government payment.
If the minister was concerned about the safety risks, the program could have been put on hold.
On each front, Mr Garrett said after the death of Mr Fuller, he relied on advice supplied by the department, much of which was distilled from meetings with experts.
Mr Garrett said much of that key information did not reach him through departmental briefing notes.
Ms Wilson described the ceiling where Mr Barnes died as a "death trap".
The teenager had just weeks of experience installing insulation, wore no safety equipment and the only supervision he received was from someone similarly inexperienced.
The death of Mr Barnes on November 18 was followed by a fatality on the outskirts of Sydney where Marcus Wilson suffered heat exhaustion while installing insulation.
In February the following year, Mitchell Sweeney would be electrocuted in far north Queensland.
Within weeks of this fourth death, the program was dumped.