On 17 April 1936, the bells of St Laurentius church in the Black Forest rang out to guide to safety a group of London schoolboys trapped in deep snow on a mountain hike gone very wrong. Ninety years on to the day, as the bells sounded again, there was hardly a dry eye in the congregation of British relatives and German villagers remembering the night that had brought together their parents and grandparents.The people of Hofsgrund risked their lives heading out with sledges and lanterns in the deadly weather to rescue the party of 27 and their teacher after two...