"I walked over and flipped it's head up from under its shoulders. It was like it was in a somersault position."
Possibly suffocated in the way that it landed,.....didn't have the energy to right itself. Been there. Retained placenta can mean nutrition deficiencies. Put out protein tubs or blocks at least 30 days before calving, look for selenium in the mix, helps calves get up and go once born. You mentioned shots? Maybe different parts of the country have different requirements, mine get grass, water, some extra protein at calving time, nothing else. Momma takes care of the calf here, I don't iodine the navel or any of that. In cold weather (0 degrees and below), I make sure the calf gets up and sucks, then I leave them be. If they suck they will still be alive come morning. My opinion is you will have more live calves if you don't line breed, and take advantage of hybrid vigor. I hope you have better luck! Feeling bad when you lose an animal, even one, is the mark of a good cattleman (woman) in my estimation. Even when running a large herd, it hurts, and not just in the wallet. Good Luck!!!!