Congratulations, You got it, JoanP. By Judith Guest, published back in the '70s. A family tragedy. Two brothers are out boating, a storm comes up and one brother drowns. The younger brother is so consumed by guilt at being alive that he commits suicide, and the book really opens when he is released from the hospital where he had gone for treatment. I don't know if there is a film or not, but it has been on TV. Guest has written other books, but none have received the acclaim of Ordinary People.