If u saw a racist attack in front of u would u intervene?

I have. When I was 16 I saw some middle school kids harassing a white girl and ran them off. I waited with her until her bus came. She thanked me and was a very nice kid. I found out later she was the younger sister of really awful racist in my class. Possibly the kids were bullying her because of him; unfair because she was nothing like him.
But she told him, and he grudgingly thanked me for protecting her.