A fire that stole the lives of four Canberrans, destroyed tens of thousands of hectares of bushland, took 487 homes from the city's families and scorched the city's soul.

Some 15 years on from that day of ash and terror, the scars on the landscape and its people remain, though recovery has well begun.

A city traumatised by fire, healing in the long tail of its aftermath.

Perhaps nowhere is this more strongly felt than in the tens of thousands of hectares of bushland across the Brindabella Ranges, Namadgi and Tidbinbilla blackened by the firestorm of January 18, 2003.

It is there where environment directorate senior ecologist Julian Seddon and his team are still monitoring the recovery - the eastern grey kangaroos and the antechinus returning just a few years after the inferno.

But it could be another 150 years before the alpine ash trees that have since grown in that mountainous terrain fully mature, developing hollows enough to support more gliders, possums and other native fauna, he says.

It was 2.45pm on that day when the official state of emergency declaration was made, as three separate fires in the ACT and a fourth near McIntyre's Hut across the border became one.

A confluence of factors; dry heat, drier bush, high winds, rugged terrain and others turning the four separate fires into what University of New South Wales Canberra associate professor Jason Sharples has called a "fire tornado".

It was no ordinary bushfire, a rare event that, he says, "evolved to develop into an atmospheric event", a plume of fire that turned into a devastating, flame-laced thunderstorm more chaotic and unpredictable than any the city had faced before, or has since.

But thanks to a host of new technologies available at the time; satellite imagery, residents photographs and videos, data and aerial scanners, the 2003 Canberra bushfires also marked a turning point for the scientific and fire-fighting community.

Assoc Prof Sharples, who is now working on the latest modelling to help predict any such future events, says before 2003 there was little understanding of the interactions between weather and terrain that could cause firestorms.

"A lot of the ways that we understood fire used to behave under the conditions were completely changed, the fact it was burning under such extreme conditions in such rugged terrain, we had no real prior knowledge of what could happen."

"We now know fire can spread and run against intuition, and a lot of these processes were discovered because of the 2003 Canberra bushfires and the research since into how these fires escalate into firestorm events.

"So we're in a much better position to look at a particular event and assess whether it's going to develop into that or not."

That lack of knowledge may have contributed to a lack of warnings and, perhaps, complacency among the authorities and in the community, a nerve that is still raw to the touch for many involved in the fire itself, and all that followed.

ACT rural fire service chief officer Joe Murphy says authorities have vastly greater capability and knowledge today than they did then - new headquarters, technology, more fire stations and equipment and improved systems among the many changes.

Three of the biggest changes he cites are the creation of a single piece of legislation governing all emergency services in the ACT, an overarching strategy to plan and prepare for, as well as fight fires, and greater resourcing.

But in the 15 years since, thanks to development in outer suburbs, massive population growth and demographic change, the city today is not the Canberra of January 2003.

And with no such major fire in the ACT since, Chief Officer Murphy fears that a lack of personal exposure to the raw destructive power of fire has again created a sense of complacency among residents.

"There are still those who will remember it keenly and will remember it tomorrow, but the population of Canberra have moved on ... many people weren't here for the event," he says.

"There is a level of complacency in our residential population [given] we haven't had, and we don't want to have another 2003."

He says residents in the "bushfire protection zone" areas developed since the fires, like Denman's Prospect, Coombs and Wright, now benefit from better planning and other measures, an acknowledgement that bushfire remains the major threat to the ACT.

Chief Officer Murphy said that this week was only the start of the bushfire season and with a major heatwave expected this weekend, now was the time to plan, especially if heading out into the bush.

"One of the continuing challenges is get people to think about bushfire danger, to sit down with their family and think: one day all of the ducks will line up and we will get another significant fire," he says.

The landscape, like its flora, fauna and people, are still healing.

One hopes the flames never return to this city, but if they do, that the alpine ash are fully mature before then.