Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 3
उत्तमस्त्वकृतोद्वाहो मृगयायां बलीयसा । हत: पुण्यजनेनाद्रौ तन्मातास्य गतिं गता ॥ ३ ॥
uttamas tv akṛtodvāhomṛgayāyāṁ balīyasāhataḥ puṇya-janenādrautan-mātāsya gatiṁ gatā
Dhruva Mahārāja’s younger brother Uttama, who was still unmarried, once went on a hunting excursion and was killed by a powerful Yakṣa in the Himālaya Mountains. Along with him, his mother, Suruci, also followed the path of her son [she died].