You can kill someone by punching them in the head if you bounce their brain around hard enough but it takes some doing. But this kid fell and hit his head on concrete, which fractured his skull and caused hemorrhaging. The hemorrhaging is what killed him. Falling down is very dangerous and leads to a lot of injury and death, especially in older people.
That said, you want to kill someone by punching them, you generally either have to hit them in the nose hard enough that some bone goes back through the sinus' in to the brain, or hit them so hard anywhere that it concusses them and causes swelling in the brain.
If you're hitting them in the body it's possible to kill someone by rupturing organs but you generally have to hit them really hard many times to pull that off. You're in a lot more danger being kicked in the torso when you're on the ground. Being kicked in the torso it's relatively simple to have organs ruptured or to have ribs broken and driven in to your lungs or organs.
You can kill someone by punching them in the head if you bounce their brain around hard enough but it takes some doing. But this kid fell and hit his head on concrete, which fractured his skull and caused hemorrhaging. The hemorrhaging is what killed him. Falling down is very dangerous and leads to a lot of injury and death, especially in older people.
That said, you want to kill someone by punching them, you generally either have to hit them in the nose hard enough that some bone goes back through the sinus' in to the brain, or hit them so hard anywhere that it concusses them and causes swelling in the brain.
If you're hitting them in the body it's possible to kill someone by rupturing organs but you generally have to hit them really hard many times to pull that off. You're in a lot more danger being kicked in the torso when you're on the ground. Being kicked in the torso it's relatively simple to have organs ruptured or to have ribs broken and driven in to your lungs or organs.
TLDR; Don't get in fights it's bad.