Moving up to camp 6 Burke had been climbing slowly and was very late in arriving. Bonington had previously suggested that Burke should retreat to Advanced Base Camp when he himself had gone back down but Burke had refused, saying he was feeling well. He was working as an assistant cameraman for the BBC and his filming was very important for him as well as for the whole team. This time Bonington told Boysen he would order Burke down but when Burke eventually reached camp he was able to persuade Bonington to let him continue. The following morning all four started the ascent but Boysen's oxygen set soon failed and he lost a crampon and so had to return to the camp. Boardman and Pertemba climbed strongly with Burke lagging far behind. The pair had reached the South Summit by 11:00 where Pertemba's oxygen blocked in the same way as had Haston's. Taking advantage of the fixed rope up the Hillary Step left two days earlier, they reached the summit of Everest at 13:10, 26 September. There was poor visibility in the wind-driven mist.