Bhav
Actually most people's first response to such events is going to be 'what if it was / glad it wasnt me, not about how many people died.
Actually it probably isn't. Our first thoughts were shock, then what a horrible way to die, then wonder what provisions are being made for hundreds of people (at best) rendered homeless and possessionless overnight.
Hopefully there'll be no more deaths, but this fire could yet be a disaster on the scale of Aberfan or the Herald of Free Enterprise. And like those it might have been possible to avoid.
As to what started the fire or why it spread so quickly, working that out is a job for the experts. What does seem clear is that something was very wrong with that block and the way it's been managed for quite a long time. Once upon a time I worked for a local authority's housing dept. for a while and our worst collective nightmare was a big fire or explosion in a tower block, resulting e.g. from gas cylinders left lying about by contractors. Memories of Ronan Point were still strong in the early 90s. Once in a while a single flat might get damaged by e.g. a cooker fire, but nothing on this dreadful scale.