A mother and a bystander who jumped into the swirling Kankakee River to save the woman's 4-year-old son both drowned, and the boy's uncle, a Marine recently back from Iraq, was missing after the rescue attempt.

The boy, Brian Santoyo of Chicago, was eventually pulled from the water and resuscitated.

Authorities said the Santoyo family and some friends were on a fishing outing near a river dam on Sunday. The river in that area can be particularly dangerous because of the undertow and eddies from the dam.

"The child apparently got caught in the undertow," Wilmington Police Chief Wally Evans said. "You see a 4-year-old go in the water and then someone goes in and then someone else goes in. I'm telling you, it's terrible here; its really terrible."

Witnesses said family members and friends formed a human chain to try to rescue Brian, but the current was too strong.

The boy's mother, Delia, 27, and bystander Alberto Medina, 28, of Chicago, both drowned. Marine Sgt. Jafet Santoyo, 23, disappeared in the water and was presumed drowned, Evans said.

Family members said Jafet Santoyo had returned recently from a tour in Iraq.

Andres Alvarez, 29, finally reached the boy and his mother and pulled them from the water but was unable to resuscitate the woman.

Brian Santoyo was in stable condition at Children's Memorial Hospital in Chicago. His father, Jose Santoyo, 28, was treated at another hospital and released.

Over the last 25 years, 15 to 20 people have drowned in that area of the river, Evans said.