[pja]

Originally the tower was built out of concrete & the outer skin of the building was glass, steel (windows & frames) & concrete. The safety case for the building was that no fire could escape a single unit, or worst case a single floor as everything in-between the flats in the building was completely non-combustible. Hence the advice to stay in place until the fire service had put any fire that happened to start in the block.

Originally it was a safe building, even without sprinklers: there have been many fires (inevitably) over the years in similar buildings which have never spread, because it was impossible for them to do so. Sprinkler systems would have made them safer & perhaps saved individual lives in the past but at no time were entire buildings at risk because of the lack of sprinkler systems, because it wasn’t possible for them to burn.

Unfortunately, covering the building in flammable insulation (!) and even more flammable rain cladding (!!) completely broke this safety case, turning the building into a death trap.