What causes pipped baby to die?

[Dandelion007]

My very first baby is a button quail. I had given up on anything hatching. I was with taking the temperature with an Accurite outside thermometer. Close to the end I figured out the actual sensor was on the bottom of the the little box that goes outside so it was much too hot. But this morning, I woke to seeing a little streak go running through the bator. It's so cute. I tried to get pictures but the plastic kept interfering with flash. Otherwise, I would have pictures. Hopefully, a few more will hatch.

Today is a very special day. This is my baby that I have ever hatched!

 

[lilbreeches]

Congrats!

 

[Dandelion007]

Okay, I have a question. One hatched this morning. It's day 16. I have read that Button Quail are supposed to hatch from 16 to 18 days. I found another one that had pipped. The baby wasn't moving. I went ahead and got it out of the shell. It had already died in the shell after pipping. It almost had the yolk inside. It was so close. What causes them to die at that point?

I have 7 more eggs and now I am worried about them.