By Pallavi Singhal, Laura Chung and Anthony Galloway
NSW Emergency Services Minister David Elliott has described this summer as the "darkest in the state's history", as Premier Gladys Berejiklian said a state memorial service would be held next month for three US firefighters who were killed when their water bomber crashed in southern NSW on Thursday.
NSW Rural Fire Service Commissioner Shane Fitzsimmons said the three men, who were all in their 40s, would be honoured at the service along with the three Australian firefighters who have also died this fire season.
Vision shows what little is left of the C-130 Hercules that crashed with three US firefighters inside.Credit: Nine News
Mr Fitzsimmons said the families of the US firefighters, who died when their C-130 Hercules crashed near Cooma while fighting a nearby blaze about 1pm, are expected to arrive in Australia at the weekend.
"These were experienced professionals dedicated to the art of firefighting ... it's a body blow to everyone in the firefighting fraternity," Mr Fitzsimmons said.
Nine News' vision of the crash site shows debris of the plane scattered across a field, with very few pieces of the plane still intact.
The investigation is complicated by the fact that fire crews are continuing to battle a number of fires in the Snowy Monaro region on Friday.
The three men were from California, with Governor Gavin Newsom saying he and his wife are "heartbroken" over the news.
The Coulson Aviation aircraft tanker was dropping retardant on the Good Good Fire, north-east of Cooma, when it went down.
The crash site is near Peak View, in the immediate vicinity of the Good Good fire, which is still listed as "out of control".
NSW RFS Monaro District Inspector Langdon Gould said two dwellings were lost in the Peak View area on Thursday.
He said fire crews would continue fighting a number of fires in the region today including at Peak View and the Rocky Plain area.
"There are number of fires still active," he said.
"We also have crews east of the containment area where there is a private plantation and heavy fuel is located."
Mr Fitzsimmons also said that six NSW firefighters who were in a tanker that flipped in Mogo on the South Coast about 11pm on Thursday did not suffer any serious injuries.
He said three of them were taken to hospital for observation and assessment and that he was waiting for an update on their conditions.
About 32 US and Canadian fire responders who have been helping with the NSW bushfire effort would return to their home countries this week.
Mr Elliott told the departing crews that "while he hopes we don't have a repeat ... of the summer we've seen, the reality is we probably will".
"You've spent a full month helping us in our time of need ... if your jurisdictions need us, let me promise you, we'll be there," Mr Elliott said.
Ms Berejiklian said the memorial service would be held at Qudos Bank Arena at Sydney Olympic Park on February 23 and would be an opportunity for the public to come together and pay tribute to the firefighters.
"We will pay tribute to the brave firefighters who lost their own lives protecting the lives and properties of others," she said.
"I know that many members of the public, the RFS, and emergency services personnel will want to come together as families and communities work their way through this unbelievable loss.
"In the first instance, it is important for us to acknowledge the ultimate sacrifices made and to move forward together on the path to healing and rebuilding."
Chuck Russell, a regional fire management officer with the National Park Service in Alaska, said that, while he didn't know the three US firefighters, he and his fellow firefighters "look at it as a responsibility we have to fight fires".
"We just feel like we're making a difference," Mr Russell said. "It's been surprising how much fire has been on the ground.
"We've been here for 30 days but Australians are here for the marathon. We want to do anything we can to let them catch their breath."
Mr Fitzsimmons said that cooler and wetter conditions would lead to a "significant easing" of the fire danger on Friday, but warned against complacency.
"There's still thousands of kilometres of fire edge ... and there's still a long way to go in this season, the statutory bushfire season may be extended," Mr Fitzsimmons said.
He said that, while monsoonal conditions in northern parts of Australia had led to a revised forecast of normal levels of rain, there was unlikely to be any "drought-ending rainfall".
"We are seeing thunderstorm and hailstorm warnings for the mountains and western Sydney. It's another difficult weather day but a different type of day," Mr Fitzsimmons said.