Count Vronsky, the love interest of the tragic main character Anna, in the novel Anna Karenina enters a stage of deep grief and mourning after her suicide. It is hard to ascertain whether his grief is caused by the guilt he feels knowing that he was the cause of her misfortunes, or whether he is actually mourning his great love, lost.
However, it is evident that her death creates a series of events in Vronsky's life that are a consequence of his deep sadness. First, his pain renders him almost unable to be proactive. He is almost paralyzed with grief, and is clearly trying to understand the situation.
Second, he turns his daughter to the custody of Karenin, Anna's estranged husband. He basically sees that his life belongs in the Army, where his heart and career have always been. In giving his daughter to Karenin, he is also returning to him (in their own peculiar way) the dignity that Vronsky took away from the man when he courted, impregnated, and eloped with his wife.
Finally, we see that Vronsky returns to the battlefield where it is understood that he will eventually die. It is a way for him to return to his origins the way that Anna returned to that one moment when she saw a man die in the railroad tracks: The two events which shaped the lives of both Anna and Vronsky repeat themselves and decide the fate of their deaths.
Immediately following Anna's death, Vronsky falls into a state of deep grief, regret, remorse, and depression, all rolled into one. It can be inferred that Vronsky partially blames himself for what happens to Anna, which is where the remorse and regret come in. He also ends up giving his daughter to Karenin, where he and Anna's son take care of her. Vronsky knows that he cannot provide young Anna with the best care possible, and having her around reminds him too much of his lover Anna.