It means that the Monastary and it's civilian casualties were a victim of a battle where thousands died. Not exactly a group of Italian soldiers inside a church who refuse to leave because they're surrounded by troops. By the way, I'm trying to contact the guy who's father was there. I left a message a couple of hours ago and I hope to talk to him tonight.
Look, the monastary was destroyed deliberately, not in a friendly fire snafu. All deaths from war are to be regretted, but you cannot equate men under arms with refugees.
My point is that the destruction of the abbey served no tactical purpose, and that this destruction was entirely elective and avoidable.
I hope you find your guy whose father was there, but don't expect this to clear up anything for you. An ordinary soldier's view of events is limited entirely to what he's seen or heard (frequently at second or third hand). I don't think there are many soldiers whose mere presence in a theatre of war confers a global understanding of what went on.