I suspect that Natalee, despondent thanks to years of teasing over the trendy and no doubt intentional misspelling of her given name, was so depressed that she forgot she could now legally correct it, and took her own life.
:-). Not a bad point.
Life for affluent suburban teens can be pretty deadening. Maybe she decided to try something different, and will turn up sadder but wiser, OR phone her family and tell them she's not coming back.