One of our cats died Saturday.
I wrote a few weeks ago that we would have to put Kimber down soon, and that's still true, though she's doing well enough at the moment that it may not be for another couple months, or at least a few more weeks.
Unfortunately, this was our other cat Springer. She had sudden onset kidney failure. Thursday she was fine, Friday she was hiding from us all day, and Saturday she was gravely ill.
We took her to the emergency animal hospital where they made it clear there was no chance of recovery; and likely there would not have been even if we had got her in there the day before; because there was no clear cause of the kidney failure. The vet said it was likely poisoning, but could have been an unnoticed congenital condition. So, we put her down.
The kids haven't really absorbed it yet.