I do believe that fire agencies in the US can be sued for negligence. I worked in Los Alamos, New Mexico, during a summer sometime in the 1990s. That summer, there was a fair-sized wildfire at Los Alamos that was started by a "controlled burn" set by the National Park Service at Bandolier National Monument. The wind kicked up, and there was a wildfire. The next year, a very serious wildfire started in the same way, and I believe the National Park Service paid compensation. If there is damage caused in the process of fighting a wildfire, that's another matter.

There was compensation paid in the wildfire that affected open mike - I don't remember whether it was the Union Pacific Railroad or Pacific Gas and Electric who paid. Both the railroad and the utility have had to pay wildfire damage claims on occasion.

-Joe-