Thank you, idk what to tell them but I'll stall for time.
Tell them what actually happened. Honesty is the best policy.
One of the key lessons in animal husbandry is assessing what went wrong and making solid plans so they don't occur again.
Your students could each draw up different blueprints for safe & appropriate chicken housing. There's a wealth of information in the coops subforum, so you can find square footage guidelines and general ideas that you can present to your class and see what they come up with.