When we went to London to film for the first episode of the documentary series "What went wrong? Countdown to Catastrophe" we were faced with much more than we bargained for. Our research had told us that the flammable cladding of the building was to blame, but we found out that the chain of decisions that led to what some have described as the whole building being wrapped in petrol actually goes back decades. Changes in building regulations, - or "deregulation" of the property development business in London - led to cost cutting on the beautification of this social housing block. Viewers will be shocked by what we found.