Why does Blanche scream fire fire?

Blanche screams "fire" as a desperate attempt to attract attention and create chaos during a moment of intense emotional distress. This outburst symbolizes her inner turmoil and the feeling of being trapped in a life that has become unbearable. It reflects her deteriorating mental state and serves as a cry for help, highlighting the themes of desperation and the struggle for escape in Tennessee Williams' "A Streetcar Named Desire."