Is the fact that other people are not doing their fair share a sufficient reason for allowing a child to die when you could easily rescue that child? I think the answer is clear: No. The others have, by refusing to help with the rescue, made themselves irrelevant. They might as well be so many rocks. According to the fair-share view, in fact, it would be better for the children if they were rocks, because then you would be obliged to wade back into the pond to save another child.