Wow, a fox.
I adore foxes, but these little buggers are not to be trusted. We wield the mighty power of the Rottweiler, and a fox outsmarts a rott without blinking or thinking for longer than a split second. It's like a tiny little dog with cat's eyes, a pompous tail and the hunger of a badger.
Just the other night, we had one that was intent to get to our neighbours tasty trash. We thought the fox was no match for our human intelligence, and we were half a dozen vs. one teeny tiny fox from the woods, with ticks and fleas and no knowledge of IR cams.
The next morning, the trash of the whole neighbourhood was spread all over said neighbourhood, mostly on the road and the sidewalks.
It hasn't killed no pets, though, so I'm still mighty fine with having a fox in the neighbourhood.
As for your question, yes, I did lose a pet.
To the feral beast that is a motorized vehicle. The cat was well flat and very dead, so the only comfort I had was that it was probably a quick death, since the road wasn't that frequented.
That was well before Pet Semetary. I'd totally have wanted to try that one out, since it was a rather bright cat. In the end, I was really glad and thankful we found it and could bury it ourselves, instead of it just disappearing. That would have given me nightmares far worse than what I'd gone through.
Not sure if it's of any use or any comfort, but know this: A cat that has tasted freedom puts freedom first, no questions asked. A cat might like your cuddling, it might respect you as someone or something that treats it nice, it might get accustomed to you feeding it. But if you take freedom away from it, you'll break it and you'll have one miserable creature. There are cats that seem to be happy as pure indoor experiences. Once even those emotional cripples get out, prepare to get used to it.
Good luck.