That's a question asked by Robert Krulwich on his blog at NPR. I won't quote his answer here, as it's not very long and I don't want to steal traffic from his blog. I highly recommend clicking over there and reading what he has to say for yourself.
However, I was unable to hold back tears at this image, which - as he points out - tells an entire story in its one-word title.
I've seen similar tragedies all too often in the flesh, which is why it struck me so powerfully. You can learn more about it at the link. Recommended reading.