How can I get an abortion?

This letter reads:

Dear Dr. Powell;

I am a 15 year old girl. I’ve just found out that I’m pregnant. I don’t want to have the baby, but I don’t know how or where to get an abortion. I can’t tell my parents because they would kill me, and never let me see my boyfriend again, or any other boy for a long, long time. Is it possible for me to get an abortion? Where could I get one? Would my parents have to know about it? Please help, as I am extremely desperate.