Condolences to the fire crews and air crew :-(
Happening all too often with aircraft mid-airs.
First assumption based on the words above, is why was the Bell helicopter (an observation aircraft it says) as low as the fire attack helicopter (Sky Crane) ?
Secondly, if tasked differently (as mentioned above), were they on the same frequency broadcasting their path, heights & intentions? Who monitors & corrects them from the ground?