My last two cats lived to be 20 and 22 and were grateful winter-rescues who ran the other way if you opened a door to the outside and the temperature out there was anything but the high heat of an August afternoon.
I had one cat back in the 60s who only lived to be 4 or 5, because a blood clot cut loose from his liver, amazingly not for a couple years after he had experienced a fall from four stories up in my previous rental apartment, an old-law walkup. He was an indoor cat from kittenhood on, with no clue about what it was to be anywhere else.
At the time of that falling incident, some idiots visiting me over the weekend had left both the window and the shutters open onto the fire escape... and the cat went exploring, fell, survived, then ran in the direction his nose was facing which was fortunately back into the inner lobby on the main floor of the building, where a neighbor had opened the door and then noticed him rushing past, caught him up and brought him upstairs. I had taken him to the vet and he was an unhappy customer, shredding a couple of their lab coats as they stitched up his tongue and then tried to x-ray him for broken bones. Pronouncing him more fit than they were by that time, they gave him back to me in seemingly good shape and joking asked me if I was sure he was "a domestic animal".
He was a big cat, but yeah domestic, just one of a litter of typical NYC cats from up on Amsterdam Avenue and lucky enough to be born indoors. He had popped out in the shirt drawer of a college pal whose Columbia law school roommate figured that was a cozy place for a stray kitty "to rest, because it was so cold out in that courtyard". Yeah, she was so cold and so pregnant and so wily and persuasive!
The owner of the shirt drawer was away visiting family and was totally unimpressed when he returned to the chore of finding homes for six kittens, the roommate having said he was sorry about the shirt drawer, while insisting he didn't really know any cat lovers. Lawyers, man...
So that cat was still one of my kitties when I moved uptown to a doorman building and he became more securely an indoor-only cat, since the fire escape of his youth was replaced by an interior fire stair door. But one day when I came home he was lying on the floor in the bedroom, probably having been horsing around with one of the other cats. Anyway he appeared to be partly paralyzed with no ability to move his hind legs. I hustled him off to the vet but I knew he was dying because those back legs were already growing cold. Poor thing, so sweet even at the end, licking my hand as I lifted him into the cat carrier. I asked for a necropsy and they found the blood clot that had spun out of his liver, plus some others still in there. They agreed the damage was probably from that hard fall he had taken so much earlier because he seemed otherwise healthy. The clot(s) were just waiting to be sprung loose at random or with some certain stressful motion during play or fighting. Well anyway otherwise he had a pretty good life on this side of the rainbow bridge. He did get along with the other kitties I had back then, so I have no idea what actually happened to him on his last day with us.