Complex sentence: Carlotta bursts into tears when Piangi is found dead backstage; the audience flees from the Opera House and Madame Giry leads Raoul to The Phantom's lair.
Split into simpler sentences: Carlotta bursts into tears when Piangi is found dead backstage. A terrified audience flees from the Opera House, as Madame Giry leads Raoul to The Phantom's lair.