How did Krishna die?

The death is told in the Mausala Parva, the sixteenth and one of the shortest books, and it is deliberately unheroic.

Two curses converge on it. Gandhari, standing among her dead sons after the war, tells Krishna that since he could have stopped the destruction of the Kurus and did not, his own clan will destroy itself in the same way, and he will die alone in a forest. Separately, some young Yadavas insult a party of sages by dressing a boy as a pregnant woman and asking what the child will be; the sages answer that she will bear an iron club that will end their race.

Thirty-six years later the omens return. The club is ground to powder and thrown into the sea, where the grains become reeds along the shore. The Yadavas go to Prabhasa for a festival, drink, quarrel over old grievances from the war, and tear up those reeds, which harden into clubs in their hands. They kill one another, and Krishna own sons die among them. Balarama walks to the sea and leaves his body in yoga.

Krishna goes into the forest and lies down. A hunter called Jara, seeing the sole of his foot moving through the leaves, takes it for a deer ear and shoots. Recognising what he has done, he falls at Krishna feet, and Krishna consoles him before dying. Arjuna comes to perform the rites and to evacuate the surviving women and children, finds his Gandiva heavy and his weapons failing, and is robbed by herdsmen on the road, which the epic uses to mark that the age has turned. The sea rises and covers Dwaraka.

Tradition treats the hunter as the rebirth of Vali from the Ramayana, killed by Rama from hiding, so that the last act closes an account from an earlier age. In Puranic chronology the moment of Krishna death is the beginning of the Kali Yuga.