Carlotta Brett-Pierce (inset) was arrested in connection with the death of her 4-year-old daughter.
The city's child welfare agency and outside care providers responsible for monitoring a 4-year-old girl found dead in her home last month are being criminally investigated, a prosecutor's spokesman said Friday.
Marchella Pierce's mother told police she found her 18-pound daughter's cold and unconscious body on Sept. 2 and tried to resuscitate her before calling 911.
The girl was born with underdeveloped lungs, had serious trouble breathing and had a breathing tube in her throat, authorities said. She had been hospitalized in the months before her death.
The Brooklyn hospital that released Marchella into her mother's custody also will be investigated, prosecutor's spokesman Jerry Schmetterer said.
The medical examiner's office is conducting forensic tests to determine how Marchella died. Marks on the girl's ankles and four lengths of rope on the bed led investigators to believe she had been tied to her bed. An oxygen mask was found in a corner.
Marchella's mother, Carlotta Brett Pierce, is charged with second-degree assault and endangering the welfare of a child. She hasn't been arraigned and no date has been set, prosecutors said. Her bail was set at $300,000 at an initial court appearance and she remains in custody, according to the city Department of Correction.
Her attorney didn't immediately return a message seeking comment.
Michael Gagan, a spokesman for the Administration for Children's Services, said the agency would cooperate in the investigation.
The outside health and social service providers the agency brought in to help the family are also under investigation.
The agency described Marchella's home care as "grossly inadequate" in a preliminary report on the case released this week.
It appeared that months had passed since agency officials last visited the girl's home, though there were signs she was at risk, the report said.
John B. Mattingly, the agency commissioner, testified before the City Council this week that the case revealed persistent systemic problems in the agency.
Two boys at Pierce's Brooklyn apartment, ages 5 and 9 months, appeared healthy and were placed in foster care.
Marchella's father, Tyrone Pierce, who doesn't live in the apartment, has said he doesn't believe Carlotta Pierce would harm her children.
Brooklyn District Attorney Charles Hynes said the 2006 death of Nixzmary Brown, a 7-year-old New York City girl who died of abuse and malnourishment, was a factor in his decision to open the investigation of the Administration for Children's Services.
"Given the history of the Nixzmary Brown tragedy and the city's failure to protect that child, I am sufficiently troubled enough by the death of Marchella Pierce to find out why she died," Hynes said in a statement.
Brown's mother is serving a prison sentence of up to 43 years for failing to act as her battered, malnourished child lay dying in their home. Her stepfather is serving 29 years on a manslaughter conviction for delivering the fatal blow.
Brown's death led to reforms within ACS intended to protect children from abuse as well as a state child-protection law signed in October 2009 increasing the penalties for an adult convicted of torturing a child, changing the maximum penalty to life in prison.