Case workers at each level of command within the city's Administration for Children's Services failed to follow up on troubling allegations of neglect and abuse in the two years before 6-year-old Zymere Perkins was beaten to death by his mother's boyfriend, according to city and state reports released this week.

In the city's report, released Tuesday night, ACS confirmed that Zymere's school reported the child's suspicious physical injuries and persistent absence from school—information that ACS failed to include in updated case files. ACS also acknowledged that it failed to contact extended family members, or "seek medical examinations for Zymere despite allegations of serious physical abuse." And while ACS was aware that Zymere's mother's boyfriend, 42-year-old Rysheim Smith, had a history of domestic violence, this evidence "should have led caseworkers to probe more deeply."

"Procedures were not followed, common sense was not exercised, and due diligence was lacking up and down the chain of command responsible for Zymere," Mayor de Blasio stated Tuesday. "I will not accept excuses for this failure and I will not accept the notion that every single one of these tragedies cannot be prevented. The buck stops with me."

Mayor de Blasio also confirmed that the city has fired three employees directly involved in Zymere's case, and suspended and demoted six others. ACS will also hire an independent monitor to be instated in January who will issue monthly reports on ACS procedure—a direct order from the state Office of Children and Family Services.

"This individual will work with the city and state to ensure necessary objectives are met as we continue our aggressive reform and strengthen our agency practices," said Mayoral Spokeswoman Aja Worthy-Davis.

The documented allegations of abuse reported this week are numerous and graphic.

In June 2015, an anonymous caller told ACS that Smith had hit Zymere "with excessive force 'at least 20 times' on his buttocks and legs for not listening while at a picnic." Zymere's mother, Geraldine Perkins, allegedly did not intervene. According to the tipster, Smith "hit the child hard enough that the source sitting at the picnic table was able to hear the slaps from each hit."

In a subsequent interview, Zymere described alleged abuse to ACS workers. From the report:

Zymere initially denied that Mr. Smith hit him. However, Zymere disclosed that Mr. Smith had placed him under a cold shower with no clothing as a form of punishment. Zymere stated that his mother was present during the incident and had yelled at him and slapped him in the face. Later in the interview, he said Mr. Smith made him do five push-ups and beat him with a belt when he misbehaved.

In April 2016, Zymere "arrived at school with multiple bruises and scratches on both legs, and while there were multiple explanations for the injuries, none were consistent with the injuries," according to the state's report. The state assessed ACS's subsequent investigation "grossly incomplete."

"Zymere Perkins was essentially tortured by those who were charged to be his caregivers," said City Councilmember Steve Levin, chair of the Committee of General Welfare, at an ACS hearing on Wednesday morning. "And those charged with protecting him... failed to do so. We all bear a responsibility as a city for his death."

Levin went on to probe Deputy Mayor Herminia Palacio, who testified on ACS's behalf. "People saw [the abuse], they reported it, they called the SCR [State Central Register], ACS did the investigation—in three instances ACS indicated [substantiated] the case. It was as if no one could see the forest for the trees. And I guess my first question is, whose job is it to connect those dots?"

Palacio, echoing the mayor, said that "in this case, the city failed." But she described the failure as anomalous, rather than systemic. "This represented an unusual perfect storm of human errors," she said.

Fifteen reforms outlined in the city's report include increased accountability over the most serious ACS cases, and retraining staff on cases with allegations of physical injury and abuse.

Perkins and Smith were arrested after Zymere's death, and charged with endangering the welfare of a child. In October, Zymere's death was ruled a homicide.

ACS Commissioner Gladys Carrión resigned this week, after three years in the post. In addition to Zymere's case, her administration also recently came under fire following the beating death of 3-year-old Jaden Jordan.

A report released by the Department of Investigation in May alleged that ACS had consistently failed to investigate and report child abuse and maintain accurate records. The report also found that ACS often took more than a month to investigate child abuse allegations.

"As Commissioner Carrión steps down, all of us must step up our push to reform the Administration for Children's Services," Public Advocate Letitia James said in a statement. "The mission to reform ACS is one we can't afford to fail. Our children's welfare depends on it."