Possible Violence, Step in or mind your own business?

Last night I heard some extremely loud noises coming from the apartment below mine. It was a constant extremely loud banging noise. Next thing I know some dude is yelling that some girl is a slut over and over again, among some other shit that I couldn't hear. Then the banging starts again and some other dude tells the guy something to the extent that he needs to leave.

30 minutes later I hear this dude outside the girls window pounding on it. The girls roommate comes out on to their porch to talk to the guy, who was probably drunk, and this girls roommate says shes bleeding and they yell at each other for a while.

I don't know what the fuck happened down their, but I feel like maybe I should have gone down there and said something while it was going on. I mean, for all I know she cheated on him and thats why hes so upset, which is none of my business. But if theres violence going on.....

I feel like I should have gone down their and just knocked on the door and checked to make sure everything was alright. Asked the dude to have the girl come to the door just so I can see that he didn't hurt her. Cause I was one of the few people in a position to do something about this guy. I mean this dude was being loud as fuck, but still, probably the only people who could hear were people in adjacent apartments to theirs and people in that specific apartment. Which would leave me, a couple other people in adjacent apartments, and the people in THAT specific apartment as the only people who could stop this guy.

Another thing. I'm a very naturally thin guy. I started lifting a couple months ago and have gained a fuck ton of strength, but if this dude has any kind of size, I probably can't take him in a fight. Should I have still gone down there? I think I should have at least checked to make sure everything was alright.

What do you guys think?