Ideally the chick doesn't hit a blood vessel. Don't panic, though, if the blood is dark colored, that is blood that was in the membrane blood vessels and it's not a danger. If it's fresh and red and there is more, that's bad.
When a chick is ready to begin hatching the head should ideally be beneath the right wing. As the chick turns its body inside the egg, the chicks' egg tooth scores the inside of the big end of the egg. Then the little peeps feeble kicks, separates the upper and lower half of the eggshell. Many times you will think that you have an unhatched egg only to realize that your seeing both half's of a fully hatched egg. When most of your eggshells left in the bator look like the one I just described, your doing something right.
What can cause dead chicks like the one in the pix. In my humble opinion Improper storage, sick, weak, malnourished or miss-nourished hens and roosters, old eggs, eggs from very young pullets, setting cull eggs, miss-functioning incubators or hatchers, human error, too much human interaction, insufficient human interaction. The list goes on and on.