Does my chick need help?

[Judy33]

I've got a small incubator with only 3 eggs in, whilst in the incubating period, there was a terrible thunderstorm and we feared that it had effected our eggs, we candled them and one seemed fine, one seemed okay and the other not so good, although no signs that it had died. It's now day 22 and 1 chick had started to pip 31 hours ago, though it's zipping diagonally across the egg, and seems that it's lying on its back inside the egg? There has been a fair bit of movement from the chick itself and it's still chirping away, but there are a couple of minutes in between where there is very little to no movement or noise from the chick. It looks like there is a crack right down the egg which has been there for a few hours, and has grown a little, but it's not really doing much? I'm really worried because this is my first time and I've been quite upset all day that I may not have any chicks, and after all its struggles, that this little chick may not survive. Please please please can someone help me with some advise or reassurance? Thank you very much.