Well I raced through that in one sitting. As someone who lives in Connecticut - within an hour from Sandy Hook, with friends who live there - this hits particularly (kind of literally) close to home. It was heartbreaking and terrifying and every other synonym. I don't have words yet. 
 ---------- 
 Full review: 
 Whew, this book was not easy. I raced through it in one sitting on a Saturday night and was desperate to see how it all ended. Heartbreaking, terrifying, and real. This won't be an easy review. 
 I'm a Connecticut resident and live about an hour from Sandy Hook... plus I have a friend who is a teacher in that town. Needless to say, this book hit entirely too close to home (literally). School shootings are something that really scare me more than I can express. When I was younger I read books about Columbine and in high school I read Nineteen Minutes by Jodi Picoult. I don't know why, but these stories have always grabbed me. Maybe because it feels like your biggest fear realized. 
 Aside from my personal connection and "interest," this book was incredibly well-written and well-done. I sat on my couch and finished it within a couple of hours; I couldn't stop. The book centers around an hour long period, from when the shooting starts until it ends. There are four main characters whose POVs get alternated between: Sylvia, Autumn, Tomas, and Claire. I won't get too much into their relationships to each other and how they related to the shooter, but they were all definitely connected. I was nervous about all of these characters and their relationships at first, but I finally got the hang of it. Despite the constant POV changes, I really felt like I knew these characters. Maybe it's because in your moments of extreme fear and turmoil, you're the most honest with yourself. They reflected on their lives and their futures while trying to deal with the terrible situation they were faced with. Even though the book was told in such a short time frame with multiple characters, I really felt their emotions and some of their personalities. 
 Yeah, this book was heartbreaking. You know that innocent people are going to die. I obviously wish certain people didn't, but it's inevitable. I won't spoil anything about the ending or characters. Regardless, I can't exactly put into words how this book made me feel. On edge, sad, terrified, heartbroken... I don't know. This story felt so real and was so well-written; I really can't think of a single flaw to take this rating down a notch. 
 I'd highly recommend this book if you're in the market for a more serious read. This could easily be required reading at schools (although I'm not sure if that would work out).