Wrecked by E.R. Frank (2005)

In this novel, the young heroine and her friend are driving home from a party when they get in a car accident that kills the other driver and leaves the heroine and her friend with deep physical and emotional scars. What I love about this book is that, unlike many YA "problem novels", it's not a book leading up to one dramatic act and then a quick resolution and "I think everything's going to be juuuuust fine." This book begins with the dramatic act and shows how hard it is to work through things. See also Life is Funny, a collection of vignettes about a group of high school kids whose lives are intertwined in intricate ways. Rich characterization, heart-rendingly complicated situations. Very moving and absorbing.