A Chelsea Piers lifeguard has been charged in the near drowning of a 5-year-old boy from New Canaan.

Zachary Stein, 23, turned himself in Wednesday to police.

According to police, the boy was underwater for about four minutes before Stein noticed him.

“There were kids swimming pretty close to him, but it went unnoticed that he was underwater,” says Lt. Tom Barcello.

The incident happened on Aug. 3.

Police say video shows Stein did perform CPR on the boy and was able to revive him. The boy was airlifted to Yale New Haven Children's Hospital after suffering seizures, and doctors say he's made a remarkable recovery.

But doctors say even though the boy is doing well, they aren't sure if he'll have any long term effects from the incident. 

Stein's attorney says he has been a lifeguard at Chelsea Piers for more than five years. He says Stein's primary concern has always been the safety and welfare of the boy.

“Not every accident or mistake is a crime, especially when dealing with first responders,” says Mark Sherman.

According to Chelsea Piers, their lifeguards have always been American Red Cross certified, but they just underwent a special training over the holiday weekend while the aquatics facilities were closed for maintenance.

Chelsea Piers had partnered with an international aquatic safety and consulting firm.

Even though a spokesperson says the training was not a result of the near drowning in a letter to its members, Chelsea Piers said it came after a "period of careful consideration."

As for Stein's arrest, Chelsea Piers says they are surprised, as he is one of the first responders credited with saving the boy's life.

Stein has been charged with risk of injury to a minor and reckless endangerment.

He's been released on a promise to appear in court later this month.