TORONTO -- A Canadian-owned water bomber being used in the fight against the wildfires in Australia crashed Thursday, killing three American firefighters.

The C-130 Hercules aerial water bomber belonged to B.C.-based Coulson Aviation, which had leased it to the Australian government.

Company president Britton Coulson told Â鶹´«Ã½ Vancouver Island earlier this month that Coulson had "pretty much all" of its aircraft in Australia as part of the firefighting effort, including two C-130s.

Authorities have said little publicly about the cause or details of the deadly collision. Rural Fire Service Commissioner Shane Fitzsimmons said witnesses had described a "large fireball associated with the crash."

According to Coulson Aviation, the plane had left the community of Richmond, Australia, with retardant for a firebombing mission.

The three crew members who were killed are all Americans. Coulson has significant operations based in Oregon.

With files from Â鶹´«Ã½ Vancouver Island and The Associated Press