Sad to read about all this.
'Interesting' how RHC changed the tanks SB to 12 months earlier, two weeks after this accident. At this rate of avoidable post-crash fires, FAA may force RHC to get AD in place instead of SB.
The ratio of airworthy machines with all stainless steel tanks versus bladder retrofitted shows the machines out there aren't reaching overhaul/major maintenance that fast.