A water-bombing Lockheed C-130 Hercules tanker aircraft crashed while fighting bushfires in New South Wales, Australia, on Thursday, killing all three crew on board.
"Tragically, there appears to be no survivors as a result of the crash down in the Snowy Monaro area," NSW Rural Fire Service (RFS) Commissioner Shane Fitzsimmons told reporters.
"[The aircraft] impacted heavily with the ground and initial reports are that there was a large fireball associated with the impact of the plane as it hit the ground."
The aircraft was chartered by Portland, Oregon-based Coulson Aviation. It said it was was "deeply saddened" by the crash, which happened as the aircraft was carrying retardant on a firebombing mission.
The state premier of New South Wales, Glays Berejiklian, called it "heartbreaking and devastating news" and said the three crew were "US residents".
"Our thoughts and heartfelt condolences are with their families and the tight-knit firefighting community," she said.
"Today is a stark and horrible reminder of the dangerous conditions that our volunteers, our emergency services personnel across a number of agencies undertake on a daily basis," she told reporters.
"And again, it allows us to consider just the circumstances people are facing every day. We have more than 1,700 volunteers and personnel in the field today. There are five fires, one in the ACT (Australian Capital Territory) and four in New South Wales, currently at emergency warning level."
The blaze being fought by the plane only began on Wednesday but had been fanned by strong winds and high temperatures.
Another fire began near Canberra airport on Thursday, disrupting air travel.