According to the Vishnu Purana, Durvasa Muni (Lord Shiva's incarnation) gave Indra a flower necklace. Indra put it on his elephant, who threw it down. An angry Durvasa cursed Indra that he would lose his kingdom. Soon enough, the world became Sri-less, and Indra and Gods lost. They all came to Brahma, who also accompanied them to Kshir Sagar. There, they all prayed to Vishnu. He appeared and advised them to do Sagar Manthan with the help of the asuras.