I'm crushed today

. I work at a dog kennel and the owners heart is in a good place and she tries to save too many animals sometimes so she has 14 foster dogs right now and probably around 15 foster cats. She recently bought them this really nice custom made cat shed/house for outside since a lot of them are feral.
We have one very aggressive pitbull named Lambert who they had in the large yard outside for some exercise and I was taking out laundry to hang on the line which is right by the cat house. Lambert somehow shot under the fence and latched onto one of our only non feral foster cats Taffy who was sunning on top of the house. I had to grab Lambert while the girl who was watching him ran to get help. It was the longest few minutes of my life as I watched this pitbull whos head was in my hands crush this basically defenseless cat (he had Taffy by the abdomen and was crushing his internal organs and back leg). I couldn't get him to let go and the cat was just thrasing it's claws into the top of the dogs head like Mufasa Lion King fighting for it's life. Eventually we choked the dog out and it let go of Taffy but he was laying panting with a bloody mouth under his house.
Everyone at my job is very pro-pitbull (I don't have anything against pit bulls) but they didn't even care about the cat or pay any attention. I was so shooken up I could barely go back to work but everyone just went back to what they were doing. When I went to the office my boss burst into tears and I had to hold her as she bawled her eyes out. I felt so helpless to console her so I told her I'd take him home and he'd be safe at my house and everything would be okay. (Even though my boyfriend hates cat and has never let me get one).
When he came to pick me up I told him about it and he was compleatly supportive of adopting Taffy and giving him a good life. I messaged my boss at 5 and she said he was back from the vet and it looked like he only had a torn muscle (no broken bones). We bought him wet food in case he couldn't eat his dry food and we bought him treats and I was going to drop them off on our way home tonight but I decided not to since I just bought my dogs a super comfy pet bed and I was going to bring that in for him with a blanket tomorrow (since our kennel doesn't really have super comfy beds) so I figured I'd just bring it all together tomorrow morning since he was probably on strong meds tonight anyway.
She just messaged me at 10pm to tell me he passed.

I am absolutely devastated. I felt such a weird connection to him. I wanted him to be okay. I was there with him trying to save him during that most traumatic incident and I was going to give him a safe home too. I was already set on him being mine and everything being okay.
Sorry to be a downer in our pet thread. I just feel absolutely crushed

. Worst day ever!