The owner of a Bronx day care center where one child died and three others had to be hospitalized after being exposed to fentanyl pleaded guilty to all criminal charges against her in court on Tuesday. Her plea came more than a year after the boy’s tragic death and the revelation that the day care was a secret stash house shocked the community. Grei Mendez, 37, her husband, Felix Herrera Garcia, and another man were arrested after 1-year-old Nicholas Dominici and three other children — ranging in age from 8 months to 2 years old — became sick from fentanyl poisoning at Divino Niño Daycare in Kingsbridge last September. “Grei Mendez has just admitted she conspired to maintain and distribute large quantities of dangerously toxic fentanyl in a Bronx day care center, a place where parents expected their children would be protected and safe,” Damian Williams, U.S. attorney for the Southern District of New York, said in a statement Tuesday. “This case has shown the senseless collateral damage caused by the fentanyl epidemic, and should remind us all that the demand for illegal narcotics so often puts innocent bystanders at risk while drug traffickers ruthlessly pursue profits.” Sam Costanza for New York Daily NewsPolice are seen at Divino Nino Daycare, at 2707 Morris Ave., on Friday, September 15, 2023. (Sam Costanza for New York Daily News) When Mendez found little Nicholas and another child unresponsive on the afternoon of Sept. 15, 2023, she first called her husband and another day care employee before finally dialing 911, prosecutors said. Police later discovered that Herrera Garcia had been using his wife’s day care as a secret stash house for his drug dealing operation since at least 2022. Federal prosecutors described how Mendez and her accomplices put the children at grave risk by using the same kitchen utensils used to prepare food at the day care as they did to package drugs. Agents who searched the day care center found a kilogram-sized brick of fentanyl and two press machines. Days later, beneath play mats and cribs where kids played, ate and napped, authorities discovered two trap doors concealing more than 11 grams of fentanyl and heroin. Mendez pleaded guilty to multiple counts of possession of and conspiracy to distribute narcotics resulting in death and serious bodily injury. The charges carry a minimum sentence of 20 years in prison and a maximum of life in prison. Herrera Garcia, 35, was sentenced to 45 years in prison earlier this month after pleading guilty in June to possession with intent to distribute deadly narcotics resulting in death and a related conspiracy charge.