An emotional New York City Mayor Eric Adams Monday denounced the suspects accused of the alleged opioid exposure in a Bronx day care last week, which left one toddler dead and sent three others to the hospital, and called for a "national assault" on the epidemic.

Day care operator Grei Mendez and tenant Carlisto Acevedo Brito were arrested on charges including murder, manslaughter and assault and ordered to be held without bail following the "reckless, depraved" death of Nicholas Dominici, 1, last week prosecutors said.

The three other victims were hospitalized, treated with Narcan, and recovering following the Friday incident, police said.

City health inspectors conducted a surprise inspection of the facility on Sept. 6 and did not find any violations, according to City Health Commissioner Ashwin Vasan.

"I'm very sorry, but one of the things that my child care inspectors are not trained to do is look for fentanyl. But maybe they need to," Vasan said at a news conference Monday evening.

Adams defended the health department during the news conference, saying they did everything they were supposed to do related to inspecting the day care, but emphasized the fentanyl crisis is growing in the city and encroaching on all walks of life.

"What are we doing? What are we doing as a society to our children?" he said. "This is total madness that we lost a child to this dangerous substance."

The mayor held up a graphic showing a small quantity of fentanyl next to a penny for scale and noted that the very tiny amount can kill an adult.

"Imagine what it can do to a child," he said.

Adams warned that the drugs that are coming into the city are not like "the drugs of yesteryear" and cannot be left lying around people's homes.

"There needs to be a full national assault on this drug entering our city," he said.

The mayor said the suspects had broken a trust people have with childcare workers.

"Part of this relationship is based on trust that those who are taking care of our children are going to do it in a safe manner. They broke that trust as others have," he said.

At their Sunday night arraignments, the judge determined Mendez and Brito were both flight risks.

The judge cited Mendez’s lack of citizenship, ties to the Dominican Republic and the seriousness of the charges leveled against her, which carry a potential life in prison sentence.

Mendez’s attorney said she was unaware drugs were being stored in her day care by Brito, her husband's cousin, to whom she was renting a room for $200 a week.

"Her only crime was renting her room to someone who had a kilo," attorney Andres Aranda said. "There is no evidence that she did anything but care properly for these children."

The judge said Brito is a Dominican Republic national who is in the country illegally and is also a flight risk.

Prosecutors said the kilo of fentanyl was found in a hallway closet outside Brito's room, near where the kids usually sleep and that Mendez participated in the "reckless, depraved act" by renting him the room in the day care. Drug production equipment was also found inside the day care, police said.

Police believe the children inhaled fentanyl particles during daylong exposure to the drug on Friday.

Authorities are also seeking Mendez’s husband for questioning.

Detectives have learned that Mendez talked to her husband several times in the immediate aftermath of Friday afternoon's tragedy.

Authorities say they have also recovered video of Mendez's husband and other people fleeing the day care with bags during the initial confusion.

The day care, for children between 6 weeks and 12 years old, opened in January, officials said.