This is (most) of A Guide to Armageddon, the 1982 BBC documentary about the effects of a nuclear blast over London, which I watched (from a copy I'd taped off television on the ol' Betamax) over and over again when I was a kid. It was made by Mick Jackson who later directed Threads, which I also watched on TV during my youth (from a hospital bed with suspected appendicitis, if memory serves; I got the all clear), the nuclear war film that made The Day After look like Disney's Our Friend, The Atom. Enjoy!