In October 2019, a single bolt of lightning at Gospers Mountain in Wollemi National Park started one of Australia's most devastating bushfires.
Little did Blue Mountains resident Greg Bourke know that two months later he would spend just over two weeks in the biggest fight of his life, battling to save one of Australia's most valuable collections of trees and plants from destruction.
As curator manager of Blue Mountains Botanic Gardens Mount Tomah, Greg was aware of the site's vulnerability. Unique in many ways, not only is the garden one of the few botanic gardens within a world heritage area, but it is also surrounded by large areas of national park, much of which is prone to bushfire.
In 2013 a week after starting the job, he had to manage operations as the State Mine fire threatened from the west. But nothing had prepared Greg for what was to come six years on.
By December 2019, the Gospers Mountain fire - which had started about 50km north of the gardens - had joined four other fires to form the 'mega-blaze' that would become Australia's biggest ever bushfire.
"We had already worked closely with the RFS managing the area around the gardens and knew it had been the worst year in history for drought, so everything was incredibly dry," said Greg, who is also a member of his local RFS.
The usually resilient eucalypts were wilting and dry.
"We closed the gardens a couple of days before the fire hit," said Greg, who also had to fight to save his own house which was heavily impacted.
"I came in to the gardens on the morning of December 15 - the day the fire hit - to open it up as an emergency refuge for local residents."
As Greg headed to the garden, his family headed in the opposite direction to the safety of Sydney's suburbs.
"Then things got really bad up here. In ended staying fighting the fire for 15 days." The inferno itself raged for 46 days.
"I never felt like my life was being threatened, but being the manager of the garden I am passionate about conservation and this was my responsibility.
I felt compelled to be here protecting these plants.
Of the thousands of hectares burnt in the "mega-blaze", the cool-climate gardens lost portions of its unique living collection and more than 90 per cent of the surrounding 186 hectares of conservation area around the garden was also heavily impacted.
"We lost over 500 ornamental plants and the Conifer collection, the North American woodland, Gondwana Forest and Darug Walk were heavily impacted," said Greg.
Fortunately, many of the garden's rarest species were spared. Areas such as the Formal Garden, Brunet Meadow, Lady (Nancy) Fairfax Walk, the Dahlia collection, the Liliums and the Explorers' Walk were also saved. The main buildings including the Potager restaurant, The Jungle Lodge and event spaces were undamaged.
Greg said he knows the word has been used a lot, "but it really was an unprecedented situation".
"It's taken a long time for me to be comfortable admitting it, but without our intervention much more would have been lost," he said.
"It really is hard to put a value on the garden's collection, but you could liken losing it it to losing Taronga Zoo and all it's animals or everything in the National Art Gallery. It would be devastating.
"The botanic garden here is a NSW asset of the people and is critical to conservation."
As Greg was helping save the gardens, the passionate photographer was also documenting the unfolding crisis - and its aftermath - with his digital SLR camera.
"I carry my camera everywhere and took photos thoughout the fire and recovery," he said.
Some of Greg's photos are now being shown at a free exhibition called Through the Smoke, Through our Eyes in the gardens until April 27.
The exhibition showcases 27 pieces of artwork by staff, residents and visitors telling the stories and experiences of those who helped defend the garden from the blaze.
Some of the images show the new growth that has sprouted up since the bushfires.
"It is nice to see the growth. It was such an incredibly intense impact and could still take around 100 years, if at all, for some areas to recover.
"While it is a long road, there are areas that are recovering - the bush is resilient. And there's lots of positivity to this too."
Greg has also photographed native animals returning into the gardens. "In the fires, I photographed a partially burned possum. It was devastating. But recently I saw possums returning. Every time you see the animals coming back it's very moving."
He said the exhibition has also been an important part of his own personal recovery.
"I was diagnosed with post traumatic stress disorder after the fire. For me the exposure to the fires again, through the photographs and exhibition, has helped - looking back and talking about it and showing visitors the impact the fires had."
Botanic Gardens Greater Sydney chief executive Denise Ora said the exhibition was a moment of reflection for the Mount Tomah team "who are not only part of the local community that was hit by Australia's largest forest fire, but also fiercely passionate people who have dedicated their lives to protect our natural environment and the gardens' regrowth".
- Through the Smoke, Through our Eyes is at the Blue Mountains Botanic Gardens Mount Tomah Visitor Centre until April 27. Phone (02) 4567-3000, bluemountainsbotanicgarden.com.au