We ALL want to know that.. Why put it in writing here?
Do you just want Pay-Back..? Don't go off all emotional, - if lessons can be learned from this, that will avoid something similar happening to another operator, ANYWHERE IN THE WORLD, give the experts a run.
While we feel your pain, - get over it, move on, and wait for an expert analysis.
That takes time, and 'Expert' sifting of the factors involved, if we are All to find out the real reasons for this tragedy.