It was the end of the day at the 1968 Mexico City Olympics - only a few thousand spectators were in the stadium as the last of the marathon runners were carried off in exhaustion to the first-aid stations. More than an hour earlier and Ethiopian runner had been the first to cross the finish line in this grueling 26-mile event. As the remaining spectators prepared to leave, they were stopped by the sound of sirens going off and policemen blowing whistles. There, entering the stadium came a lone figure wearing the colors of Tanzania - his name was John Akhwari. He was the last man to finish the marathon.