Is that the yolk sac?

[Erka97]

He hatched naturally but 24hrs late. I have 2 more trying to hatch

Assuming that chick is still alive, you'll need to remove the remains of that yolk and stop the bleeding from the chick's belly, and make sure all the organs are inside. You may also want to put anti-biotic on the wound to prevent infection, but make sure it is not the pain relief kind. Then return the chick to the incubator. If it lives, it will need food and water as soon as possible due to not having yolk to live off of. I had a duck that was like that once because her egg got pecked open by chickens, and I managed to save her.