Thanks!

Trying to help Lily to get up after that accident was unexpected, I've got a background in medicine and was trying to locate any broken vertebras, her spine was not broken off clean, but still ended up dying from it, maybe the pain...

I'd think that a cat might be more intelligent and prepared to leave at any time, something similar happened to a kitten, maybe a cat that understands that it won't be able to walk again will just leave.

It was when I flipped her around and saw sand in her open eye that I knew she was dead, now her body is nutrition for a nice tree we planted a few years ago :-)

And of course maybe she is back as one of the new, tiny kittens!