Lord Krishna’s pastime of removing the yadu dynasty is ultimately auspicious.

“Many demigods, coming to the earth to assist Lord Kṛṣṇa in His pastimes, took birth within the Yadu dynasty and appeared as Lord Kṛṣṇa’s associates. When the Lord had completed His earthly pastimes He wanted to send these demigods back to their previous service in universal administration. Each demigod was to return to his respective planet. The transcendental city of Dvārakā is so auspicious that whoever dies there immediately goes back home, back to Godhead, but because the demigod members of the Yadu dynasty, in many cases, were not yet prepared to go back to Godhead, they had to die outside the city of Dvārakā. Thus Lord Kṛṣṇa, pretending to be an ordinary living being, said, “We are all in danger. Let us all immediately go to Prabhāsa.” In this way, by His yoga-māyā Kṛṣṇa bewildered such demigod members of the Yadu dynasty and led them away to the holy place Prabhāsa.

Since Dvārakā is parama-maṅgala, the most auspicious place, not even an imitation of inauspiciousness can take place there. Actually, Lord Kṛṣṇa’s pastime of removing the Yadu dynasty is ultimately auspicious, but since it outwardly appeared inauspicious, it could not take place in Dvārakā; therefore Lord Kṛṣṇa led the Yadus away from Dvārakā. After having sent the demigods back to their planets, Lord Kṛṣṇa planned to return to the spiritual world, Vaikuṇṭha, in His original form and remain in the eternal city of Dvārakā.

Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura has made the following important comments on this verse. Prabhāsa is a famous holy place located near the Veraval railway station, within the region of Junagarah. In Chapter Thirty of the Eleventh Canto of Śrīmad-Bhāgavatam it is written that after hearing the words of Śrī Kṛṣṇa, the Yādavas went to the mainland from the island city of Dvārakā by means of boats and then traveled to Prabhāsa in chariots. At Prabhāsa-kṣetra they drank a beverage called maireya and became engaged in a mutual quarrel. A great battle ensued, and killing each other with hard stalks of cane, the members of the Yadu dynasty acted out the pastime of their own annihilation.”

Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Eleventh Canto, Chapter 06 – Text 35.