Because we keep referring to the cubs as babies, we might be doing them a disservice. The word 'baby' suggests something tiny. Bear cubs are not tiny. A full-grown bear - one the size of the mother - can weigh close to 1500lbs. These cubs were nowhere near fully grown, but they were still large.
To add to the problem, their fur was heavily soaked by the water, and so they had water weight to deal with, too. Something powerful was needed to help them out.