Do not support the word, and the willingness to help and protect. Just to be with the person in a difficult moment in itself valuable. You know the universal words of support that would normally say, "I'm sorry", "sympathy", "Over time, everything goes", "Time heals" and similar expressions. But by themselves they are not able to calm the man, if he does not feel sincere participation.
Before you say anything, think about what would comfort you in this situation. Man must somehow "hook" for the future, show a new goal, to which he will seek. The woman that her husband left her after twenty years of marriage, feels that her life is over. She did not really see the point in my life and not just a need to support, and in concrete terms, how to get out of this situation with dignity.
The words "Calm down, everything will be" do not need to say, they have no future. We can say that in forty or fifty years old woman begins to live only for themselves, grow and arranging children. At this age, having a rich life experience, much easier to choose the person with whom she will live a happy life. Suggest a joint shopping trip and a beauty salon, to deserted wife was able to meet his destiny head-on.
If someone has died from close friends, get close and help with funeral arrangements. Sometimes a person can be derived from a state of despair, placing before him a series of questions and tasks that need to be addressed. Talk about a close friend in need of him, in his support. Drew his attention to what he should also help their relatives. Taking on the role of comforter, one he will find words of support and feel the responsibility for the family.
Sometimes it is enough to say: "I am always with you, no matter what happens! ". These words can say and not waiting to happen something bad.