Kulverstukas:
You've got the facts straight but, although I agree that the cause can certainly be INSIDE, I think we can't fully exclude structural causes followed by fire (causing passenger injuries etc.) completely yet. If you think we can I'd appreciate to hear your reasoning. We know many results of what happened but lack the sequence of events and therefore certainly do not know the start of it yet. The key piece of the puzzle is still missing...
Please keep up the good work!
I think we're getting close to having enough facts to draw harder conclusions.