How true, Chris!!!
Laura, its great to hear that your family is recovering from the incident, especially the kids. Perhaps you should consider yourself lucky not to have seen the boat again - it was very depressing. The wood still shown brightly, but the upperworks was all knocked askew, and yet there was no evidence at all of fire damage. It was a very, very strange sight...
That seems odd that the boat was just taken away like that - did Certified know where it went or who took it??? Do they have authority to take it away without your knowledge. The boat was shrinkwrapped and its upperworks removed before it was transported, so it didn't look like they just haphazardly hauled it away...
Regarding possible causes, we were discussing some early on in this thread. Not knowing you (and you seem like a knowledgeable, experienced boater!) we took stabs at possibilities ranging from owner negligence to various defects/malfunctions...
Did you have a propane system onboard? Or portable gas grill tanks somewhere? Perhaps that system leaked and was ignited by a spark. Another thought was that, given the location of the fuel lines (pretty much right under where you were sitting near the cabin bulkhead) it seems possible that leaking gas vapors traveled "downhill" under the cabin sole and ignited there. My old Carver had no bulkhead dividing the engine room and the bilge spaces under the cabin, so fumes could conceivably have traveled there. My newer boat notably has that bulkhead in place, to separate the two areas...
Of course, even with the leak we still need an ignition source. Do you have any comment about the authorities' assertion that the alternators were not ignition protected (marine grade) units??? Again, not knowing you we thought that perhaps on a recent overhaul you might have replaced them with automotive units not realizing the threat of a spark igniting bilge vapors. I'll admit that news of your mishap prompted me to go check my own alternators, since I had bought the boat last year and frankly had no clue as to what the previous owner had done in that regard...
If in fact these were automotive alternators, perhaps you have a case against whoever sold them to you, if you were under the impression they were marine grade. Just a thought...
I remember another possible source was mentioned as a loose coil wire. That would be a shame, as it is so preventable, but it is also quite common and can happen easily. If we're smart we have all checked our own engines after the news of your mishap...
Regardless, I hope you get an amicable insurance settlement and get back on the water again when the time is right. Meanwhile, Godspeed and good health, and I hope the kids have great years in school!!!