Can I be fired because I heard my boss yell that I was an f---Btch and I called him on it?

Today I was suppose to meet with a client and my boss told me to reschedule, so I did. I was in my cube working on other issues at hand, when I heard the owner/my boss ask another employee why I left her (she was to go to appt. w/ me orig.) did not hear what she said, but another employee said that I wanted to leave early so I wouldn't be late. Which was the original plan. After she told him that He yelled at the top of his lungs in front of everyone in the middle of the office "that f...Btch, I told her not to go! That f...Btch!" I couldn't believe what he had said and even though i was shaken up, I calmly came around my cube and said, "excuse me?" and he looked at me and said, "I thought you left." And I asked again, "excuse me, what did you say?" and he repeated himself yet again. And I said, “It doesn’t matter whether I left or not, what did you just call me?” And he didn’t answer. Then I said, “I didn’t deserve to be called that whether I am here or not, I might as well not even be here and he said " that's fine leave your key on your way out." So in a nut shell all of us have been putting up with these kind of outbursts since we all started in August. We have seen, heard and dealt with much stress from him and it has to be stopped. I hate to go legal but he can't keep making people afraid of him. Also, we have all been working OT at straight pay, he failed to tell us he doesn't pay x1/2 for OT but expects OT during busy season. So I do not have a job and can not collect unemployment. Please advise as to what can be done and if anything and if so, if he would be responsible for the bill as well. I know for a fact this duress has put alot of stress on my relationship and on the others families as well.