SB 10.11.49

kṛṣṇaṁ mahā-baka-grastaṁ
 dṛṣṭvā rāmādayo ’rbhakāḥ
babhūvur indriyāṇīva
 vinā prāṇaṁ vicetasaḥ
Word for word: 
kṛṣṇam — unto Kṛṣṇa; mahā-baka-grastam — swallowed by the great duck; dṛṣṭvā — seeing this incident; rāma-ādayaḥ arbhakāḥ — all the other boys, headed by Balarāma; babhūvuḥ — became overwhelmed; indriyāṇi — senses; iva — like; vinā — without; prāṇam — life; vicetasaḥ — very much bewildered, almost unconscious.
When Balarāma and the other boys saw that Kṛṣṇa had been devoured by the gigantic duck, they became almost unconscious, like senses without life.

Although Balarāma can do everything, because of intense affection for His brother He was momentarily bewildered. A similar thing is stated to have happened in connection with rukmiṇī-haraṇa, the kidnapping of Rukmiṇī. When Kṛṣṇa, after kidnapping Rukmiṇī, was attacked by all the kings, Rukmiṇī was momentarily bewildered, until the Lord took the proper steps.