at race checkpoint stations. By 14 April, the fourth and longest leg of the marathon, spanning over , Prosperi had maintained momentum. By early afternoon, he had left Manzo behind and increased his pace, to rank in a position of fourth place. Temperatures that day had peaked at . Due to the intensity of the sun's rays upon the sand, Prosperi experienced a rise in heated surface air, which in return created swirling winds that were able to travel at rapid speeds, due to the large expanse of the desert. Feeling the increasing effect of the wind, at into that day's run, he began to cut across small sand dunes to increase his pace. However, stronger gusts of air began to lift the smaller dunes, clouding Prosperi's vision and amounting to a severe sandstorm. In fear of being submerged by the sand if he remained stationary, Prosperi continued to run for the entirety of the storm, which lasted eight hours, determined he was able to see the marathon trail. In an interview with Men's Journal Magazine in 1998, Prosperi said: "When the sandstorm started to blow, I lost sight of everybody else. I kept running, though, because I thought I could see the trail. I was in seventh place and didn't want to lose my standing. It was nearly dark before the winds relented. I started running again, but after a few minutes it occurred to me that I had lost the trail."Due to the intensity of the windblown sand grains upon his skin, Prosperi experienced bleeding within his nose and injuries in his throat, whilst breathing in the particles of sand. It was not until that evening, following the storm's passing, that he stopped to rest by sheltering in a bush and covering his face with a towel. The following morning, the winds had halted. He awoke and continued to run for four hours, convinced he would find other competitors of the race. However, following a climb to the summit of a tall dune, Prosperi was unable to identify any other participants, and furthermore realised that all signs and landmarks indicating the race trail had disappeared following the storm. By this time he also noted the liquid in his water bottle depleting and attempted to drink the remaining water in his bottle as slowly as he could. This method however, was not sufficient to maintain his hydration levels. Remembering