Witnessed a child being abused and I feel so helpless

[Breezycheesetrees]

I'm not sure what I'm hoping to get from this really. I overheard a young boy being yelled at and threatened with having his pants pulled down by the older woman he was with (presume grandma). He was about six. He was really distressed and looked physically not in good shape, he was asking for water which seemed to be what the argument was about. At the point where she roughly shoved him over a wall and began pulling his pants down so she could "slap his arse" I intervened, tried to speak to the boy and offer him water but he was terrified and just wanted me.to.go away. The Grandma was furious and verbally abusive to.me too. He had a little sister with him. There were other witnesses but nobody else got involved. As she hurried the kids away I rang the police; they took it seriously and sent patrol cars, but later rang back to say they couldn't find them. I can't get that poor little boy's face out of.my head. What could I have done better? I've just made things worse for him haven't I?

Please don't do this. No one needs Facebook vigilantism.

You did the right thing, OP. Sometimes we're left wondering in life. Hopefully others know the family and are also stepping in to protect the children.

You did what you could OP. I've never witnessed anything quite that awful but I've witnessed a few really horrible things and it stays with you for a really long time.

It was outside the hospital in a city centre so he could be at school literally anywhere in the city. I don't know the area, but I think there are a couple of primary schools in the immediate area they were walking towards, so it's worth thinking about a bit more.
I'm not going to do the Facebook thing although I did consider it out of desperation. But a witch hunt wouldn't help anyone.

It doesn't have to be a witch hunt. I wouldn't even describe the people involved or state their genders. If someone witnessed the incident they won't need that sort of detail.