How terribly frightening for your nephews to have witnessed. No, you can't make up for something like that, those scenes and terror are now a part of them, their experience.

No one deserves to be mistreated in any way.
I'm sorry this happened.

You were about to be on your way to living on your own soon. That must be kind of scary to think about and to have happen in the way it did.

How are you doing now?