Three Americans have been killed after their aerial water tanker crashed while battling bush fires in the Australian state of New South Wales. The Rural Fire Service confirmed a C-130 Hercules tanker came down while fighting fires in mountainous terrain near the town of Cooma. “All three occupants on board were U.S. residents,” said Commissioner Shane Fitzsimmons, according to the Washington Post. “We simply lost contact with the machine and the flight tracker we used stopped—there is no indication at this stage what caused the accident... It has heavily impacted 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 plane was reportedly operated by Coulson Aviation, which is based in Canada. Prime Minister Scott Morrison expressed condolences to the “loved ones, friends, and colleagues of those who have lost their lives.”