A baby blackbird flew into our house through a window, our dog attacked it and it looks quite bad. What to do?

It flew in, Sandy pounced on it, but not knowing what to do, didn't do too much. But now it looks like it can't fly and I don't know what to do. It's too late to go to a wildlife sanctuary tonight, so can anybody give any advice? (btw, we've put it on top of the shed for the moment, just in case it's alright and the parents come looking fot it)