What does Wayne Butler reveal about the fire in which Will's mother was killed in the novel, The Marriage Lie?

Wayne lived in the same apartment building with Will and his family and strongly believed that Will was responsible for the fire. He said that he lost everything in the fire. He remembered that when Will had seen his father brought out of the fire and realized his father was not dead that he looked disappointed. Wayne thought Will had intended for both his parents to die in the fire.