A “hero” mother of six drowned saving her 4-year-old son after he fell into a river while trying to get a lost toy, according to police and her heartbroken children.

Nicole Grayson, 43, fearlessly jumped into the St. Johns River Saturday at a park near DeLand in Central Florida to rescue her son, who fell in while leaning over a low wooden fence to get a toy that had fallen into the water, according to the Volusia County Sheriff’s Office.

A boater who heard Grayson’s cries rushed over to help and pulled the boy out as Grayson slipped below the surface.

Nicole Grayson died diving into a Florida river to save her 4-year-old son. GoFundMe

He was eventually able to get her aboard and a good Samaritan immediately began performing CPR — but she later died at the hospital.

“I love my mom,” Grayson’s devastated 9-year-old son, Koron, who was at the park with his mom and brother that day, told WESH.

 “She did all of that for my little brother. She pushed me aside because she didn’t want us to get hurt. She saved my little brother, but she didn’t worry about herself. She worried about my little brother.”

Grayson, who worked as a hospice nurse, was a proud, loving mother of her six children.

“She was always there for you,” Grayson’s 17-year-old son, Dafino Devega, said. “She would have [done] that for any of her kids, and we would have done the same for her.”

Marc Swartz told WESH he was the only boat on the river at the time when he heard someone yelling for help. He rushed over and tossed Grayson and her son life vests.

“I was able to maneuver my boat over to them, and I was able to grab the boy. I put him on the boat, and I grabbed the mother, tried to. She was already under,” Swartz said.

John Reaka was nearby when he heard the commotion and ran over.

He helped pull her onto the boat and “started doing CPR and mouth-to-mouth, trying everything I could to resuscitate her and everything in my power to bring her back,” he said.

Grayson, 43, worked as a hospice nurse. GoFundMe

“It’s just sad what happened. It really is. It’s a tragedy,” he said. 

Grayson’s eldest daughter, Montraevia Adams, has since launched a GoFundMe to help cover funeral expenses.

“My mom was literally my hero,” she said.

“I just want her to be remembered as a positive person because she always had a smile on her face no matter what,” Adams added.