When the caterpillar becomes a chrysalis, that is called "pupation." So, your caterpillar pupated. When the butterfly emerges from the chrysalis, it is said to have "eclosed." Black Swallowtails will overwinter as chrysalides. The breaking of the silk girdle isn't necessarily a problem, depending upon when it broke. If it broke while the cat was actually in the process of pupating, there is not much hope. If the cat successfully pupated the chrysalis hardened, and then it broke, you are probably fine. Hard to know without seeing a pic of the chrysalis. You could just keep it inside a container in your garage over the winter and see what happens in the spring. As long as the eclosing butterfly has something to climb up onto when it ecloses, it will be fine. You can even make a little "ramp" using a paper towel and lay the chrysalis right next to it. I believe that I got all that right. Someone else can add or ammend as needed.~~Angie

Oh dear, it was while he was pupating. It hardened in the angular position. :-(

Did the little guy fall to the ground while he was pupating or was he still partially attached to the stick?Can you snap a pic? Is it a really big bend? If you are not sure, just put the chrysalis into a container, and into the garage, and see what happens in spring.
It's fine to bring those Black Swallowtail cats into the house when you find them late in the season because we know that they will overwinter in the chrysalis. The key thing is to move them to outside temps once they have pupated so that they don't go ahead and eclose in the warm house during the winter and then can't survive outside. I keep mine in my garage during winter, and they usually eclose sometime in April. You do have to remember to check the containers often once spring comes. I just put mine into a spot where I will see them often as I go to and from my van. Other people put them outside in containers. Some even put them into the frige.~~Angie

I would like to see a pic - it may be fine, as I think the BSTs are like the GSts I have raised and they actually have a little bend in them when they form into chrysalis.