What do Fireworks represent?

The fireworks are symbols of better times. Emmett remembers the happiest day he spent with his parents at a fireworks display in Seward. After Billy was born and Emmett’s mother lost interest in everything, his father made her attend the fireworks display. She cried and squeezed Charlie’s hand as the fireworks were detonated. She realized from the display that she had the ability to live a happier life if she was willing to leave the life she was living behind.