An ex-boss would make one team member cry every other day and was buddies with two other toxic teammates who also bullied him and previous teammates (who quit before I was hired--I didn't know any of this history). There was screaming and shouting (like "holy shit should we call security?" kind of fighting) and ex-boss would just close her door instead of doing something about it. She tried to frame the one Black team member for something and he eventually quit.
I took copious notes and kept every chat and email containing or reporting inappropriate behavior and reported her ass and other toxic teammates to HR. I even surreptitiously recorded conversations (state law allows this). Because of the field I was in at the time, HR and legal had to get involved. Four people were fired, so at least something good came out of that stupid experience.