My friends are fighting?

(All names in this are fake) My best friend, let's call her Kat, is having a fight with my friend Cara. Kat and I are auditioning for a play, and Cara had auditioned the day before us, so Kat asked (through a text) what the audition song they made you sing was. Cara then replied, very upset, saying why should I tell you? Kat texted back "I just wanted to know, jeez." For some reason, Cara got really mad at Kat so now both of them are angry at each other. Then, my friend Michelle, started hanging out with the both of them, since Michelle is friends with both Cara and Kat. But Kat felt like Michelle was taking sides, and got mad at Michelle. (Michelle is actually taking sides, because she thinks what Kat did was "wrong.") Now, I feel really upset because Kat dragged me into this and I feel like its sort of my responsibility to help these guys work it out. The problem is, I think Cara was kind of wrong in this situation. Kat just asked Cara to tell her the song, but Cara got mad. I want to help them, but I feel like Cara and Michelle should be the ones apologizing. How can I help my friends? Or should I just stay out of it and let them fight?