What should i say to her about this situation?

last night i was sleeping and then rudely interupted when my roomate and her boyfriend were having and enormous argument. i dont know what exactly the problem was but they were in the room and he was yelling at her hard and constantly. im not talking about little arguments that couples have because thats normal. but he was seriously attacking her with harsh words calling her a b*tch, sl*t, and was extremely loud. and she was just there crying her eyes out literaly and he was going on and on. when she tried to get a word in and explain he would cut her off and continue yelling. I had to leave the room but i stayed outside and they just kept arguing and she sounded like she was throwing up and he just kept going on and on..than after an hour he left the room and slammed the door and then she went to her friends room. should i ask her what happen?? aparently they have been together for a year but what i saw doesnt look like a relationship at all. neighbours complained about it too, you could hear him yelling and her crying all the way down the hallway. what advice would you give? should i tell her to break up with him?