PLACE: London, England
GOOGLED: "next of kin" + "notification" + "military"; "casualty notification" + "military; "casualty notification" + "history"; "death notification" + "history"
I need to find out how a surviving family member would have been informed of a loved one's death at war (in the above time/place, c. 1900 London). My educated guess would be by telegram, as I believe that's how all notifications were done through at least WWII, but I may be incorrect about that (or that may have only been the case in the United States). Actual text of the notification isn't necessary (though it would add a phenomenal detail to my story); I'm looking more for a general answer of "by telegram"; "by post"; "they'd send an officer"; etc. Thanks in advance for any assistance you can give me.
(Also, I strongly doubt it matters, but in case it does: it's irrelevant to the story whether the character died in battle or from injuries/illness, so even if you only have information for one of those situations, that would still be perfect.)