Sad book about girl that survives a car accident but her sister dies?

I looking for a book I read years ago about a girl dealing with her sisters death after a truck kills her. Details from the book that I remember: girl dying in a tunnel, dead girl's favorite candy was sneakers, tunnel in which the main character goes in with dogs living inside it, a boy and her trying to speak to her dead sister. If any of these things ring the bell tell me the name of the book.