According to Mahabharata, the Kurukshetra war resulted in the death of all the hundred sons of Gandhari. On the night before Duryodhana’s death, Lord Krishna visited Gandhari to offer his condolences. Gandhari felt that Krishna knowingly did not put an end to the war, and in a fit of rage and sorrow, Gandhari cursed that Krishna, along with everyone else from the Yadu dynasty, would perish after 36 years. Krishna himself knew and wanted this to happen as he felt that the Yadavas had become very haughty and arrogant (adharmi), so he ended Gandhari’s speech by saying “tathastu” (so be it).
Accordingly after 36 years passed, a fight broke out between the Yadavas, at a festival, who killed each other. His elder brother, Balarama, then gave up his body using Yoga. Krishna retired into the forest and started meditating under a tree. The Mahabharata also narrates the story of a hunter who becomes an instrument for Krishna’s departure from the world. The hunter Jara, mistook Krishna’s partly visible left foot for that of a deer, and shot an arrow, wounding him mortally. After he realised the mistake, While still bleeding, Krishna told Jara, “O Jara, you were Bali in your previous birth, killed by myself as Rama in Tretayuga. Here you had a chance to even it and since all acts in this world are done as desired by me, you need not worry for this”. Then Krishna, with his physical body ascended back to his eternal abode, Goloka vrindavan and this event marks departure of Krishna from the earth.
The news was conveyed to Hastinapur and Dwaraka by eyewitnesses to this event.
The place of this incident is believed to be Bhalka, near Somnath temple.
According to Puranic sources, Krishna’s disappearance marks the end of Dvapara Yuga and the start of Kali Yuga.