Oh Kirsten......how heartbreaking for you, especially to see the other kitty nearby just staring. I'd fall to pieces in an instant. RIP little kitty. {{{HUGS}}} to you.

I wonder if you could borrow a scanner from the vet and scan for a microchip. Did you see if there was a tattoo? Mind you, if I were in your shoes I'm not sure I would be able to touch it. You are much stronger than I. Just don't know what else to say....it's all so very sad.