For me a very important reason, or the one that impacted me the most, was when Hannah decided to inform Mr Porter about the rape case and he told her to ignore it.
She was there to have a las chance. She was there to try to forgive the world and forgive herself, but Mr Porter broke that last chance and took with him Hannah's hopes.
She felt her world falling down while she was walking back to her class with her will of helping broken. The good action she could have done to safe the girl, Jessica, and to safe her life was taken away by this teacher who refused selfishly to help one of his students. When hannah finally commits suicide, there's a big feeling of shame, Mr Porter decided not to come to school for days because he realized what he had done but he could never imagine the repercussions it would have.
But once Hannah is dead, there are no chances, the last chance was the day Hannah came to his office, but he didn't take use of it.
I know the girl who was raped was not a "Lady" or an "angel" but no one deserves something like that, she was too young to have her life destroyed so soon. Maybe she would't commit suicide as Hannah did, but she will have to live with fear and psychological injuries for the rest of her life.
In my opinion, Mr Porter not only helped to destroy one life but two, Hannah's and Jessica's, he can't have a work like that whose main function is to help his students. Maybe he learnt and realized what he did and he will find another job to avoid destroying more teenager's lifes.
