Appendicitis itself won't kill you unless you refuse to get medical treatment for the appendicitis.
When the appendix becomes perforated and left untreated then the appendicitis can kill you so it's very important to get medical attention right away as soon as you experience symptoms of a burst appendix.
If you or someone else experiences the symptoms of appendicitis, especially sharp pain in the lower right area of your abdomen, get prompt medical care.