Black Saturday taught Australia much about the "wicked problem" of bushfires, but experts argue last season's unprecedented blazes have highlighted more needs to be done.
The 2009 Victorian fires killed 173 people, and a subsequent royal commission led to far-reaching improvements in bushfire preparation and response across Australia.
But there was clearly not enough in place to hold back the fires of 2019-2020, which although not as fatal, were far more widespread and enduring. The Black Summer fires engulfed four states over three months on their way to claiming 33 lives and destroying more than 3000 homes.
Another royal commission opens this week and is due to report on last summer's catastrophic fires before the prospect of another deadly season looms later this year.
With each devastating blaze and subsequent inquiry over the past century, the experts learn new ways to deal with bushfires. But each fire also reveals there is still much to learn.
"We thought we understood how to deal with bushfire, but Black Saturday showed there was still so much we did not know," Bushfire and Natural Hazards Cooperative Research Centre CEO Richard Thornton says.
"Of course, things have improved - a quick glance back at the way the 1983 Ash Wednesday fires or 2009 Black Saturday fires were handled shows much has changed."
Dr Thornton said there has been a fundamental readjustment of thinking in the emergency service and land management agencies over the decade since Black Saturday, based on sound science and research.
And the next royal commission must readjust it all again.
Dr Thornton says bushfires are a wicked and complex problem.
"There is no silver bullet for bushfire safety, or indeed for all natural disasters."
Planning expert Michael Buxton, who gave evidence to the Black Saturday royal commission, says everything from fire prevention and suppression to evacuation must be re-examined.
The approach must be more integrated than anything done up until now, including the results of the 2009 royal commission, he says.
"We now need a radical reappraisal of the ways that we've approached both preventing of harm to people and tackling the fires themselves," the RMIT emeritus professor said.
"We've now moved to a completely new situation, with massive fires burning on a major part of the Australian land mass on broad fronts that just overwhelmed all our assumptions."
The Black Saturday royal commission's 125 recommendations sparked sweeping national changes, including improved warnings and better coordination between emergency response agencies.
But debate continues over key issues such as hazard-reduction burning and managing the risk in bushfire-prone areas.
Bushfire expert Kevin Tolhurst said overall, the royal commission has probably been as successful as many of the other 56 formal inquiries and reviews related to bushfires and fire management since 1939.
"About a third to half of the recommendations have actually made some real change, but the other half to two-thirds have been only partially or certainly incompletely applied," the University of Melbourne associate professor said.
Dr Tolhurst, who worked in the Integrated Emergency Coordination Centre on Black Saturday and testified at the royal commission, said there was a significant difference between ticking off a recommendation as being addressed and examining whether it had achieved the intended outcome.
He noted some recommendations from a royal commission into Victoria's 1939 Black Friday bushfires had still not been fully implemented, pointing to the inquiry's call for land management agencies to be at arm's length from government.
"What we need is action on what we already know - use the knowledge we've got, use the recommendations that we've had in the past and be fair dinkum about implementing them in a way to achieve the outcomes that were intended."
Professor Alan March, an expert on urban planning for risk reduction, said Australia has come a long way but just using the solutions developed 10 and 20 years ago may no longer be sufficient because the threat and risk is worsening.
"We might need to go back to the drawing board, even though we've made good advances on a number of fronts, and rethink what level of risk we are prepared to tolerate," the University of Melbourne and Bushfire and Natural Hazards CRC researcher said.
The royal commission into the 2019-20 bushfires begins with a ceremonial sitting on Thursday.
Australian Associated Press