A man and a woman are presumed drowned after they were dragged away by a fast-moving, icy river in Sioux Falls as they tried to save a 6-year-old child.

Rescue crews along the Big Sioux River in Sioux Falls, South Dakota (KSOO, Townsquare Media)

Sioux Falls Fire Chief Jim Sideras says emergency crews searching the Big Sioux River at Falls Park changed their focus from rescue to recovery early Friday.

Sideras says the boy was climbing on rocks Thursday evening when he fell into the frothing water. The boy's sister jumped in to save him but was swept away. A man also jumped in to help but he disappeared into the freezing water.

Sideras says witness accounts differ on whether someone pushed the boy out of the water or he popped up on a rock before being pulled ashore.

Authorities have not released their identities.

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