Leadbelly, my sincere condolences on the loss of your little Buttje.   I lost my 5-year-old Melanie LaMew similarly, to a driver who was going too fast for our little 2-block (between stop signs) residential street, even though Melanie (reportedly) did run right out in front of her car.   


On the subject of "caging" cats, I agree that, especially in some areas, cats really need to be kept indoors for their own safety and perhaps for the sake of the birds.   But Melanie, like the venerable Grisabella, who adopted me shortly after Melanie's death, spent her formative years on the street before adopting me and was not at all content to be perpetually caged.   I did routinely bring her inside before dusk, as I do Grisabella, but that particular day I fell asleep in the late afternoon and did not wake up till later in the evening, after she had already been hit.   
My maternal grandparents were farmers, who always had outdoor cats, largely to keep the mouse population in the barn under control.   Barnyard cats (and kittens) do get carried off by coyotes or hawks or stepped on by cows, but that was a hard fact of life that I learned to accept as a child. As for city cats, I'm not sure which one is worse off - the street-wise outdoor (or indoor-outdoor) cat or the indoor housecat who "escapes" one day only to find she or he has no clue as to the ways of the outside world.   In any event, while I see the benefits to keeping cats as strictly indoor pets, I think there are benefits both to cats and to the human community by letting some of the felines roam outdoors sometimes.

It really does leave a hole in your heart when a beloved furry family member dies, whether in kittenhood or at a ripe old age.   I am very sorry for your loss.

Genie