A relative of the young boy who died said he slipped in after he tried to get a ball that went into the river, and that the boy's mother did everything she could to try to save her child.
One witness, who did not want to be identified, saw the boy in the water after hearing his mother screaming.
"She turned around and was screaming, and by that time, I was like, 'Oh, my God, what's going on?' I jumped out of my car, and I'm looking, and I see this baby floating down the river," he said.
This happened just after 3 p.m. by the docks near the Kankakee Valley Boat Club.
"They were on the dock, playing. There was a ball involved. The ball went into the river, and the young child jumped in to retrieve his ball, and the mother, they did their best, but they just couldn't reach the child," said Kankakee Police Department Chief Chris Kidwell.
The Kankakee Fire Department, along with other nearby jurisdictions and bystanders, all jumped into action to help, but officials said the river's water levels were high and the current was strong.
"Under normal circumstances, the river is still quite dangerous, but after the rain we've had in the last couple days, it makes the current much stronger, the water much murkier, and the debris coming down is much more dangerous," said Kankakee Fire Department Chief Bryan LaRoche.
The witness ABC7 spoke with said after two people jumped in to try to save the child, he too did what he could.
"I have these long cables in my car and so I said, 'If I could just get these cables out to this young baby, maybe they can grab a hold of them, and I can pull him to safety,'" he said.
But when he turned around, the man saw the boy go underwater one last time. About 2.5 hours after the 6-year-old went missing, his body was found.
"Anytime you lose a life, it's difficult, but when it's a young boy or girl, that's probably even more tragic. They haven't lived their full life yet," said Kankakee Mayor Chris Curtis.
The witness ABC7 spoke with and officials are hoping this incident reminds people of the potential dangers of the Kankakee River, especially after the impact of the recent round of storms.