I came home and found my beloved Husky/Wolf hybrid of 12 yrs dead and ripped up by two of my other dogs...why?

I once witnessed my Husky/Wolf hybrid almost kill her mother when she was old and had cancer--she survived for another year before finally showing me she couldn't go on any longer. I now have found her daughter, some ten years later, all strung out along my fence with heavily trodden snow and lots of blood where my 9yo Great Dane ***** and my rescued 6yo English Mastiff had killed her--she was a really good fighter, but her aged body wouldn't do what she needed it to do and she finally succumbed to the two attackers. I have one more older Great Dane who has Wobbler Syndrome and she has holes in her as well, but is slow to make it down stairs where the dog door is to the outside. There was no food, or anything to fight over--the only thing I did differently was to liberate some stuffed toys from the top of one of the book cases the night before--so there were lots of stuffed toys on the floor. The rescue Mastiff was bounced around the lower 48 for a while, then brought up to Wasilla and had been squirting out puppies every time she went into heat--I became aware of her plight and she was so shy at first, yet kept reaching out to me when I was there (hanging out with her owner; an acquaintance/used to be friend of mine--I was watching his dogs for a while). Shiloh was always the one that would come to me, then run off if I even moved to wipe my face--I felt sorry for her and decided to give her a good home. Since then, she went from hardly any coat at all, and black with puppy mill grossness to an incredibly healthy female with a huge heart for me as well as those whom I show her are okay. She has become the protector of the house..I am the only human here, and there are four dogs--the Husky/Wolf , Tanker, 12, a rescue Great Dane 8, a show Dane 9, and Shiloh, the Mastiff,6. I knew that there was a bit of tension between the two, but tTanker would always defer to Shiloh when it came to the bed and other stuff, while Shiloh would defer to Tankier when it came to a toy, or being first to get a treat--they seemed to have it all worked out splendidly and got along fine for a year and a half before this happened. I am really good at being in tune with my dogs and they never gave me any indication that this was brewing at all. It is that time of year when the sun begins to feel like California, yet it is still frigid at night that spawned this? There is always a big leap in suicide, homicide, murder rates up here around March, April, and May...it is when the body wakes up and the mind has been hibernating for the winter--now you have energy and find out that you are depressed and can actually do something about it. I have had three of the four (minus the mastiff) get into a gang fight while being kept at another person's house around the same time of year, a few years ago. I moved my dogs there and used the remaining two kennel runs for them--split them up two by two...one morning I let them all out into the big yard only to find all four fighting horribly. It didn't seem to matter which one fought with who, they would break up when I hit them with ammonia but go find another partner and start another fight. I finally picked away one at a time...that was in late March, or around the same time of year as now. I cannot bare to see my nine year old Great Dane as dainty as she seems, nor can I bare to see my rescued Mastiff who now is proudly sporting a healthy new coat and has a small roll of fat on her from Innova dog food; they are outside and I blocked the dog door. Single digit temps and only the two of them on snow or cement-their choice for the night...they can snuggle up together--it makes me feel better knowing that they have to put up with some misery since my beloved Tanktank is in a plastic bag all frozen in the back of my truck out there as well. It makes me sick! I nourished and loved all of my dogs and I know they have no tolerance for weakness within the pack, but they all knew where they belonged...could it be that the Mastiff waited for me to leave before confronting Tanker for whatever reason? Why did the two dogs have blood covering them--obviously ganged up on her--there's a lot of very disturbed ground, about ten feet long where Tanker finally was cornered and brought down then brutally killed-she went out fighting to the death and was only able to slash the two other dogs a few times...a couple deep puncture wounds around the head on the Mastiff and a shredded ear on the Dane--the rest is all Tanker's gut pile and one huge rip along her neck with jellied blood--her face was frozen into a snarl. Tank was defiant and baring her fangs to the end! If I were only home!!!! Can I still love the other two dogs after this? I almost shot them both already, but couldn't since I have loved them for so long--does two or three deaths avenge the one? Will the Mastiff soon decide to attack and kill my eight year old Dane with Wobbler's Syndrome next time, or was she simply just ta