Actually, we're neither warm-hearted nor brilliant. Let your friend cry until she comes to her senses. There's nothing you can do about it.

Did you receive personal gifts (something belonging to her) from your friend ? This could be a sign she actually has bad intentions to leave the world. Assuming the danger could have some ground, try to give things to do to your friend, let her feel committed to something sane, make her believe that time can mend such things. Repeat her that : a) this experience is shared by almost all human beings b) almost everyone recovers and in due time enjoy their own happy family c) you will be in awful and in-natural pain if your friend hurts herself How about getting in touch with her parents ? Be practical: -- your friend might not know that the big suffering (caused by what seems a failing romantic relation) is actually caused by the sudden stop of endorphines production by our brain. In the state of reciprocal romantic and passionate love, these chemicals abound in our brain; when the relation stops we get pain as these substances immediately and drastically drop their concentration; it is like heroin addiciton, but less severe, as it is "natural"; all these words to tell your friend to believe that time will surely readjust this dramatic chemical unbalance; Please seek about dopamina, endorphine, love, neurotransmitters over the internet, you will get more ground and credibility. === end of transmission; (obviously, as you say the situation is serious, I take you by your word!)

Let the time heal the wounds.. I don't think anything else would help.. (Just make sure she does not commit suicide - to the best you can)...

I think you can do your best to comfort her, such as 带她出去逛街，吃东西等等，只要不让她觉得孤单就行了。