You make a good point. (I don't know if it applies here, but generally it is true)
My first hens were from a place that breeds for commercial poultry farms and long lifespans are not the goal, so I have had to deal with lots of health issues. They were unnaturally good layers and that gave...
I am so sorry this happened to you :(
If you feel up to it, please update the post with what you learned. Maybe your babies lead to someone else saving theirs by learning from your experience.
I sincerely hope there were no more deaths in your flock, it is hard to live with.