How terrible, my heart goes out to all who've lost a pet especially in such awful circumstances.
We do our very best to protect our little one's but such is life that we can never know just what's around the corner. I know of two greyhounds that turned on and killed a little Yorkie while the owner (an old lady) was walking it.
Having a Yorkie or any small dog is rather like having a toddler that never grows up.