Complex sentence: Upon arriving home, Kimberly has a vision of a flock of pigeons attacking her, and she and Thomas rush to save Nora and Tim, but they arrive too late and Tim is crushed by a glass pane at the dentist.
Split into simpler sentences: Upon arriving home, Kimberly has a vision of a flock of pigeons attacking her. Kimberly and Thomas rush to save Nora and Tim, but they arrive too late and Tim is crushed by a glass pane at the dentist.