THE BRONX, N.Y. (PIX11) – The father of a 1-year-old boy who died of fentanyl poisoning after he was allegedly exposed to the drug at a day care in the Bronx said he never imagined the facility was being used to hide an illegal drug operation.

Otoniel Feliz, the father of Nicholas Dominici, spoke publicly on Thursday about the tragedy his family has endured. Nicholas was one of four children who were exposed to fentanyl at the Divino Niño day care in the Bronx on Sept. 15, according to authorities.

Feliz said he trusted the day care’s operator, Grei Mendez, because she constantly kept the family informed about their child. Mendez would “send us text messages” about “every little thing that happened throughout the day,” the father said.

“We feel betrayed because [Mendez] showed us that it was a place you could trust, that she was going to be like a mother for our son in that time,” Feliz said. “But all of this was a screen for the huge business that they had going on in the back: the drugs. That’s unacceptable.”

Mendez, her husband, and her husband’s cousin were indicted Thursday for murder under circumstances evincing a depraved indifference to human life, assault, and other charges in connection to the case. Each of them pleaded not guilty.

Investigators found a kilogram of fentanyl stored on top of children’s playmats at the day care, as well as large quantities of suspected narcotics in hidden trap door compartments in the floor of the room where the children played and slept, according to authorities.

“You leave your child in the hands of these day care providers, you expect to be able to pick up your child at the end of the day. But instead, this family comes there, and now their child is dead,” Bronx District Attorney Darcel Clark said. “These people used a day care as a front for a drug operation. This was not really a day care center. This was a drug operation, and they used babies as a shield in order to run that operation.”

Divino Niño was a home-based child care center that opened under the official authority of the New York State Office of Children and Family Services, according to New York City Health Commissioner Ashwin Vasan.

Vasan previously said the New York City Health Department conducted three inspections at the day care on behalf of the state, with the most recent one being a “surprise” inspection happening the same month the fentanyl poisonings occurred. No violations were found at the day care during that most recent inspection.

The Bronx district attorney said she’s going to look into how the alleged drug operation was overlooked during the inspection.

“I want to investigate how it is determined that people can open up these home day care centers, their regulations, rules, licensing. I’m going to look into all of those things to see if there are any gaps, are there things that they are missing, things that should be part of these inspections that haven’t been before,” Clark said.