Alright... help please?

I have a best friend, who means the world to me. We've known each other for a long time and she has always been there and vice versa. Lately some stuff has happened. She has had two close friends die in the last 3 months and is taking it really hard, which I can understand. One of her other friends is suicidal and will probably die soon as well, and that is not helping the situation at all. She has started cutting. I told her she needed to stop, and she said that she never would again but the last time I saw her she had 5 cuts on her arm. I don't even know about her legs or anything. I live about an hour away from her, so I don't see her very often at all. She recently got banned from talking on the phone or via internet, so I can't even talk to her at all. I'm seriously worried that's she's going to commit suicide due to all this and the fact she is writing vivid death poems. Her parents don't know most of this, yet I'm not sure how I would go about telling them. What should I do?!

Well you will eventually have to tell them otherwise you're right, it's likely she'll commit suicide.

I have to say point out to her how her pain may effect others and reasons to live. Suicide is giving to me. Tell her if she dies how will it effect other people. It wont help the situation it can only worsen it. Let her know you care. Tell her that her friends that died wouldnt want her to die because of them.

Suicide is a childish thing for cowards, those who do it only let down other. huh, suicide, i hate the word, i once wanted to do it. But there is always a new day.

Thank you, everyone, for the advice. Much appreciated.