Chera Small says she tried to comfort the boy's mother.
"She just said she wanted to die," Small said. "I said you didn't do anything wrong. You didn't do anything wrong."
Not far away, rescuers signal that they have found something in the water. There was a rush to help and after an hour and half of searching, they found the 10-year-old boy.
"He was walking along the sand bar, he slipped off the edge and went to 8 feet deep," said Stanley Gaskey, Underwater Rescue & Recovery Unit. "He went from 3 feet of water to 8 feet of water."
Once they pull the boy onboard a boat, rescuers perform CPR, attempting to resuscitate him. They transport him to a nearby hospital.
The mother was overwhelmed with emotion.
"It's just so heartbreaking," said witness Mary Anne Milkowski. "I can't even describe it."
"It was very eerie and have a police officer take her back - the screams were heartwrenching," said witness Toni Milkowski. "It's horrible."
Police say the 10-year-old boy came to the lake with a 13-year-old friend and his mother.
"This particular lake is a non-swimming lake," said Hammond police Lt. Richard Hoyda. "There is security, if they encounter people swimming in the lake. They would tell them to leave."
Rescuers warn, too, that adults and children must take precautions.
"You can only be in water waist deep and have problems, you should really have a lifejacket on to protect yourself - it's very sad," said Amber Kissinger.