How can I help my friend? Her parents treat her like crap?

I guess I know what your friend is going through. My father was like that, tightly wound, agitated at every small thing, called me stupid, incompetant, idiot, etc. I would say the first thing that leads up to the "thick tension" that could be cut by the aforementioned butter knife is the younger brother. Since he has special needs, her parents have high expectations for your friend which contributes to them getting angry about small stuff. I guess they are also worried about your friend's safety. When you guys were late did you tell your parents that the train was late right away? or did u wait until you got back home? Since they are seemingly paranoid, or busy with the brother, make sure your friend tells the parents everything, like where she is, why she is late, etc. The relationship between my dad began when I was in middle school and sort of ended Sophomore year in high school. In my case, it was my crappy grades. Your friend needs to find what is upsetting her parents the most. The tension and anger towards small, seemingly trivial things, are a reaction to some action she did that ticked them off. My dad always said "actions speak louder then words" so negotiating probably isnt that great of an idea. I'm guessing that major action is her not being as responsible or careful or communicative as her parents want her to be. Every family is different, so do not see her parents as evil or misguided, though it may seem that way. My solution for now, is to ramp up communication, almost exagerate it so as to tell her parents that she is really trying to fix something. For example, when your friend goes out somewhere, she should send text updates or something, call them once in a while for an update, etc. She can only fix the problem if she can empathize with the parents. getting angry and talking back will only make matters worse and prolong the issue. I hope this helps. I had to go through 5 years of this hell....