I am looking forward to the accident report. From the drag path the a/C had significant forward speed when it impacted the ground, borne out by the cockpit remaining sufficiently intact for the pilots to escape.
I suspect they got caught by windsheer near the fire resulting in them being on the wrong side of the "power available/power required" curve leading the a/C to impact near horizontal.
Coulson have had a run of accidents in Australia, acouple of years back they lost a C-130 and crew. They have also lost two 412s, thankfully without losing any crew.
Fire fighting is dangerous work.