"There had been no casualties, fortunately."
Translation:Não tinha havido baixas, felizmente.
Yeah this is an annoying misunderstanding. Casualties really can't mean just deaths, it means killed and wounded otherwise you'd say how many dead/killed/exterminated/. In a military setting it means specifically someone that can no longer fight. That can be for many reasons on top of the rather obvious one of being dead, it could mean sickness, being wounded, captured, run away...etc