I haven't found any mention of John's passing here and the search function turns up nothing. According to a post by Ed Webster on Supertopo, John died at home in the UK on March 30.
Turner was, I think, among the good climbers of the Brown/Whillans generation, but he came to the US, studied at MIT, and went to work as a chemist in Canada before returning to the UK in 1962.
Turner made a series of ascents at Cathedral Ledge and the Adirondacks in the East and Bon Echo in Canada that were futuristic by the US standards of the day, but he received little recognition from a climbing community that thought the center of progress in the US was in Calfornia. Turner was well ahead of the Californians of the day, both in boldness and technical difficulty.
But he hasn't been forgotten over on this side of the pond, and there is a substantial appreciation of him on SuperTopo that now stands as his climbing memorial. It's worth a read;
http://www.supertopo.com/climbers-forum/999872/John-Turner-Appreciation-Thr... .