Two pilots have made a "miraculous" escape after their Boeing 737 water-bombing plane crashed and burned while fighting a blaze in remote Western Australia.
The plane left a long scar in the scrub- and tree-covered landscape when it came down while battling a bushfire in the Fitzgerald National Park about 420km southeast of Perth.
Aerial images taken shortly after the accident, which happened on Monday, showed thick black smoke spewing from the aircraft on the ground, with the rear of the fuselage consumed by the inferno.
The impact had left a long sand-coloured trail through the greenery behind the plane.
Emergency services images captured a short time later showed that the tail section had separated from the rest of the aircraft, which lay in cinders.
The two pilots were released from hospital a day after the accident. They have not been identified although officials said they were believed to be North American.
"It is nothing short of miraculous that they were able to walk from that plane," the state's emergency services minister, Stephen Dawson, told a news conference on Tuesday.
"We are very grateful that they are healthy and, well, it is a truly remarkable outcome. And it is probably testament to their skill as pilots."
The large air tanker, a converted passenger plane, hit the ground only about 20 seconds after completing a water drop in the area, officials said.
An investigation has been launched by the Australian Transport Safety Bureau, which said it was the first "collision with terrain" involving a Boeing 737 in Australia.
"It is a remarkable outcome that both of the crew have managed to get themselves out of the aircraft and are safe and well," said the bureau's chief commissioner Angus Mitchell.
The safety regulator would be interviewing the pilots and witnesses, as well as looking at maintenance records, weather conditions, and the task underway at the time, Mitchell told a news conference a day after the crash.
"A large aircraft going down is generally quite catastrophic," he said.
But in this incident, the plane appeared to have clipped a ridge and "pancaked" to the ground, he added.
"Certainly a horizontal landing as opposed to vertical into the ground makes a big difference."
Investigators hoped to get access to the crash site from Wednesday if it was considered safe, and to recuperate the flight data recorder and cockpit voice recorder, Mitchell said.
There had been 64 firefighting aviation accidents over the past five years with the safety body looking into lessons to be learned from those incidents, he added.
The investigation would focus on ensuring procedures were as rigorous as possible "to keep the crew safe" Mitchell said.