Hello brwestcoast..... the nearest I can get to my hide and seek disaster could possibly have been summer 1952??. I cannot remember being at school in a plaster cast, so must have been school holidays. The place was deserted but not yet in the process of demolition. Had there been any activity from either working engines or demolition we would not have been there.
Sorry I am unable to be more accurate, best of luck with your book.
p.s. Now that I think back there seemed to be quite a long period between work ending and demolition starting.