Mute Witnesses

What is with our society today? People mind each other's business so much except for when it really counts. Today I read an article about a little girl in AZ. Her family locked her in a box for taking a Popsicle out of the freezer without permission. You can read the full article here. The article goes on to quote "witnesses" who had seen her being abused in the past to include the child being forced to eat dog feces. I want to know if they saw this why did they not at the very least contact the police or child services? Why did they wait until after she died to say anything? What kind of people are they these witnesses?