How did gene react when finny dies at the end of a separate peace?

After Finny's death at the end of "A Separate Peace," Gene feels a deep sense of loss and regret. He is devastated by Finny's passing, as he has lost not only his close friend but also a significant part of his own identity. Gene sees Finny's death as the end of a chapter in his life and experiences a complex mixture of emotions, including guilt and sorrow.