Depends on the age & maturity of the class. A high school class might benefit from a lesson on the realities of life & nature, a pre-school class probably would not. Did they get any healthy chicks to hatch? Those should be left with the class, for the kids to watch them grow. Those unhealthy chicks should at least be kept separate, at least for the chicks' benefit, to have some quiet & freedom from stress.
I don't know if the bleeding one will make it, the one with its intestines outside most likely will not. Someone will have to cull one or both, to end the chicks' suffering. It's always a shame, when they make it through incubation & get themselves to hatch, only to have these impairments. You could wrap the chick in a paper towel and cut its head off with a sharp pair of scissors. I find it easier to do that with the chick wrapped, it's so heartbreaking to view.
I'm sorry for your son & his classmates, this is not the happy ending anyone wanted for their long project. At least it should help them appreciate the real miracle of all the healthy chicks that did hatch. Maybe it would help them to bury the chicks under a favorite bush, to give their matter to the growth of something else.
