Oh Gertie, that is so sad.
There are a few possibilities. It seems there are more foxes and badgers in urban areas than there used to be, so it could possibly one of those. I would have thought they would have eaten it, though, unless it was a young fox/badger. The other thing it could have been is a stray dog – if one could access your garden. A dog managed to get into my garden a couple of years ago (not sure exactly how) and fatally injured an adult hedgehog, so it does happen. I am guessing you don’t have a night cam?
Fingers crossed for the other little ones.
