Why does the hanging of the boy affect elie more than other deaths

During this section of Elie's story he relates the affect that a hanging has on them. They arrive back from a work detail and they are called into formation to witness a hanging of three prisoners. This particular hanging is worse than the others because there is a boy being hanged. There is a graphic description of how the bodies dropped and the ropes tightened. The men died almost immediately, but the boy was too light and he kicked and wiggled and didn't die right away. It took a long time and they all had to stand and watch the entire dying process.