If violence only includes harm to humans, I think you could probably reasonably say that destroying an empty hospital is still violence since the direct effect

If violence only includes harm to humans, I think you could probably reasonably say that destroying an empty hospital is still violence since the direct effect of destroying the hospital would be to harm the people who would otherwise be treated there. Tbh though I think destruction of property reasonably counts as violence; the more important question is whether that violence is justified. In this case it seems justified.