Krishna stops when almost all are destroyed. Babru and Dhaaruka approach him and tell him, 'Swami so many are dead! Let us go and meet Balarama'. They find him in a lonely spot, supporting himself against a tree. He is alone and deep in meditation!.
Krishna asks Dhaaruka to go to Hastinapura ; 'Tell them about the occurrences here and ask Arjuna to come quickly'. He tells Babru; 'Go in a hurry to Dwaraka. Take care of the women, the thieves will try to loot and trouble them.' As Babru hurries towards Dwaraka a hunter's trap kills him. Krishna seeing this tells Balarama 'Wait! I will be back shortly.' and goes to Dwaraka and meets Vasudeva. Tells him, 'Appa! Arjuna is coming and take care till then. Balarama is waiting for me and I have to go! Earlier we saw the destruction of kauravas, now it is the yadavas. I cannot bear to be in this lifeless city. I will go and join Balarama and do penance in the forest.' Krishna leaves after prostrating at the feet of his father. On his way out, he hears wails of dead yadavas' children and women and consoles them with, 'Arjuna will be here! Calm down! He will solve your difficulties.' He keeps moving and goes back to see Balarama.
On reaching the place, Krishna sees that Balarama is absorbed in profound meditation and soon a thousand headed serpent emerges out of his mouth and merges into the occean. The heads of the nagas and god varuna welcome him. After loosing his brother, Krishna thinks of his future as he wanders in the empty forest. As he sits on the ground he remembers Gandhaari's curse and feels that the time of his departure from life is near. He controls his senses, speech and mind as he gets absorbed in meditation and lies down. Jara, a hunter mistaking him to be an animal shoots an arrow at him and pierces his body. The hunter nears the body and realises that he has shot Krishna and deeply contrite at his great mistake, touches Krishna's feet and Krishna breathes his last.
Krishna and his story is well known, but I quote from wikipedia:
According to Bhagavata Purana, Krishna was born without a sexual union, but by divine "mental transmission" from the mind of Vasudeva into the womb of Devaki. Krishna belonged to the Vrishni clan of Yadavas from Mathura, and was the eighth son born to the princess Devaki, and her husband Vasudeva.
Mathura was the capital of the Yadavas, to which Krishna's parents Vasudeva and Devaki belonged. King Kansa, Devaki's brother, had ascended the throne by imprisoning his father, King Ugrasena. Afraid of a prophecy from a divine voice from the heavens that predicted his death at the hands of Devaki's eighth "garbha", Kansa had the couple locked into a prison cell. After Kansa killed the first six children, Devaki apparently had a miscarriage of the seventh. However in reality, the womb was actually transferred to Rohini secretly. This was how Balarama, Krishna's elder brother was born. Once again Devaki became pregnant. Now due to the miscarriage, Kamsa was in a puzzle regarding 'The Eighth One' but his ministers advised that the divine voice from the heavens emphasised "the eight garbha" and so this is the one. That night Krishna was born in the Rohini nakshatra and simultaneously Goddess Durga was born as Yogamaya in Gokulam to Nanda and Yashoda.
Since Vasudeva knew Krishna's life was in danger, Krishna was secretly taken out of the prison cell to be raised by his foster parents, Yasoda and Nanda, in Gokula.
The story reminds me of a question a precocious kid put to his teacher: 'If Kamsa knew about the risk he ran from the eighth child of Vasudeva and Devaki why did he imprison the couple together?' It seems Bhagavata Purana anticipated this question!
It is also fascinating to read about Krishna's last days. His frenzied attack and his total withdrawal after the wanton destruction of the yadavas. Krishna who was always one to help, now tells his father and the women of yadavas that it is Arjuna who would come and take care. Gods decide when to step in and when to step out of a situation!