My duck family is gone...

Today, when I came back from work. There is no ducks calling me for food. I thought they were just playing too hard and not knowing the time. So I went to the house and started to cook. When my husband started to get food for them and he could not see anyone around. He was surprised. so he went to look for them. He found our duck prince was lying by the side of the garden hardly move. He was serious injured. He started to look around for others, but not a trace of them. He was keep looking since he would not believed they were all gone.
When dinner is ready and I went out of the door and calling him: "Dinner is ready for you." He said motionlessly: "They are all gone."
"What do you mean they are all gone?" I asked. He Finlay awake and said: "The ducks all gone. only the boy is by the garden and hurt so badly."
I hurried to the garden and see our duck prince lying in the grass and lifeless. I picked him up and told him: "Don't worry. I got you. You will be fine." I took him to the house and use the bath towel dried the rain and blood. and swaddled him using the bath towel. He seemed a little comfortable. and Then, we took him to the animal urgent care and the doctor did not think he has much chance: he was serious injured by some animal on chest, back and neck. he is in shock. Finally, we decided that it is the best to put him to sleep as soon as possible so he would not suffer more. The doctor did it and we took him back home and berried him with our dog Arlington.
The others probably were eaten by the animal attached them.
My poor ducks! They never made any troubles and they gave us eggs all the time. They have been live with us for over two years! What did they do wrong to get this treatment!!!!
I am so sorry and I am so sad...