Read em and weep. But literally. Go on, I'll wait.
....
This is called a crural hernia, or femoral hernia. A hernia occurs when a portion of the abdominal organs (usually intestines) protrudes through a hole in the abdominal wall. In this case, the uterus was torn and the tissue separating the thigh and abdomen broke (both likely via trauma), squeezing the kittens into this empty space at time of impact.
Good news is mother cat actually survived. Bad news is all of the kittens did not. On top of the cord likely being severed, they would have internal injuries and blunt force trauma on top of being premies. Even on x-rays some of them appear to be obliterated, so I am not surprised. I honestly am shocked that momma cat made it.
#vetmed