Child Abuse

Let's say you had a neighbor with two children and every time you saw those children, they looked like crap. Running nose, hair not done, dirty clothing and nails. Meanwhile the parent; their mother looks great. Fresh outfits, hair and nails done; latest designer bags etc. At least every other night you're hearing screams from them being beaten and you are aware that they don't go to school. What would you do? Intervene or you'd rather not get involved for fear of what may happen to you?