STAMFORD, Conn. (CBSNewYork) – An unprecedented criminal case is unfolding in Fairfield County, Connecticut.

A lifeguard, credited with saving a young boy’s life, is now being charged for putting him in danger.

As CBS2’s Hazel Sanchez reported, 23-year-old lifeguard Zachary Stein helped save 5-year-old Adam Khattak, who nearly drowned at a splash pool at Chelsea Piers in Stamford. But police weren’t praising Stein’s actions Wednesday; they arrested him for endangering Khattak’s life.

“There are certain distractions with kids splashing and what not, but this is a small pool, and we believe it should’ve been noticed sooner,” said Tom Barcello, of the Stamford Police Department.

The American Lifeguard Association said this is the first time a lifeguard has been criminally charged for a near-fatal drowning.

“Zach saved this child’s life. He was the first person to pull this child out of the water and administered life-saving CPR,” Stein’s attorney, Mark Sherman, said. “Now you just can’t make every accident or mistake a crime.”

Stamford police said they reviewed surveillance video, showing the child under water for nearly four minutes. Police said fewer than eight other children were in the pool and Stein was the only lifeguard stationed there.

“He did do his lap, like he normally does, but he just failed to see the kid underwater,” Barcello said.

When Stein finally saw the boy, police said he jumped in and helped perform CPR, reviving the child.

Chelsea Piers released a statement, saying, “This was a terrible accident. We are surprised to learn of the arrest, particularly when the lifeguard charged was one of the first responders, who has been credited by the Stamford Police and others with helping to save the boy’s life.”

“He wasn’t drunk, he wasn’t texting, he wasn’t talking to other girls or other lifeguards or other people. He was doing his job,” Sherman said.

Sanchez spoke with Khattak’s mother at their New Canaan home, who said her son is recovering well. She declined to comment on what happened at the pool or the lifeguard charged with endangering her little boy’s life.

Stein has resigned from Chelsea Piers, after working there as a full-time lifeguard for five years. He’s charged with reckless endangerment and risk of injury to a minor.