DHS took away two of her kids. She jumped from a window with the third in her arms.

Early in March, Felicia Hickson seemed to be unraveling. She complained of hearing helicopters overhead. Neighbors saw her standing in the open window of her North Philadelphia home looking up at the sky. She also had been using drugs, again.

Then, on March 8, she appeared to snap. High on PCP, with her 2-year-old son in her arms, Hickson flung herself out of a second-floor window, according to police.

The toddler suffered face and brain injuries. Hickson now sits in jail on attempted-murder charges.

City officials concede that the boy never should have been in her care: Four years earlier, Hickson's repeated drug problems had led child-welfare workers to remove her two other children from the home. Last year, a judge deemed her unfit to get them back. And all along, the Department of Human Services took no steps to remove her youngest child.

"How is it that … even though the mother is incapable of taking care of two other children, it's perfectly fine to leave this child in her care?" asked Sam Gulino, chief medical examiner for the city and chair of the state-mandated Act 33 team that reviews child deaths and serious injuries. "If the parent can't care for two of her three children, they likely can't care for three of three."

DHS administrators insist that the case has been a wake-up call. The caseworker and her supervisor have been fired. Attempts to ease caseloads are ongoing. And a new DHS policy requires another level of scrutiny of similar households by city lawyers.

But Hickson's case raises new questions about one of the more complex challenges for the agency: supervising children in such "split families," where at least one child is taken away and another remains at home. But the agency, which with an annual budget of $640 million is responsible for about 10,500 children, can't say how many split families are under its supervision, making enforcing any policies problematic.

"Despite our best efforts we can't pull every data point," DHS spokeswoman Heather Keafer said.

Since 2007, seven children died or nearly died in such homes that had been under DHS supervision. The Hickson case was the first such case since 2013.

In 2009, Joshua Gallop was beaten to death by his father in his mother's home. Joshua's mother had previously lost custody of one of his siblings and another spent time in foster care.

In 2012, after the abuse and starvation death of 6-year-old Khalil Wimes, investigators determined that five of his siblings had previously been removed following reports of child abuse.

That same year, a woman from whom the agency previously removed four children took her latest, an adopted baby, into a hospital after the little boy had a seizure. Investigators said the mother could not say when she last fed the child; there was no formula in her home.

In Philadelphia, and nationwide, child welfare agencies try, whenever possible, to keep children with their families, especially if a family's issues are related to poverty rather than abuse or neglect.

And DHS administrators note the agency does not remove one child just because the parent has lost custody of another. In some cases, a mother or father may be fully capable of taking care of one child but is overwhelmed by a sibling who has truancy or behavior problems. Oftentimes, struggling parents are able to care for children later on.

DHS has been aware of the balance. An agency review of Khalil Wimes' death noted: "Whenever parental rights are terminated on a sibling, behavioral health and wellness should be consulted to determine whether a parenting capacity evaluation should be completed before the return of any other children."

The policy created in response to the Hickson case requires an immediate home visit if a new child comes into a family DHS has been working with. The caseworker must consult with the law department in case action is required — a step officials say may have prevented the Hickson case.

"It doesn't mean in every case the child is removed only because a sibling is already in care, but it clearly outlines the steps they have to take," said DHS Commissioner Cynthia Figueroa.

Despite the lack of data on such families, Keafer said caseworkers will be instructed to apply the policy to their cases and DHS will attempt to monitor that through quality-assurance checks.

Richard Gelles, professor of social policy at the University of Pennsylvania, said DHS doesn't need a new policy; rather, he said, it needs to use an existing federal law that allows for the immediate removal of a child in extreme circumstances.

Gelles helped draft that law, known as the Adoption and Safe Families Act. In a system built on keeping families together, the law allows for certain aggravating circumstances to fast-track removal if a child is in danger. One of those aggravating factors is if a parent has involuntarily lost custody of a child.

"We know for certain that past behavior is the best predictor for behavior," Gelles said. "So why did everybody turn a blind eye to mom's past behavior and think that her substance-abuse and mental-health problems are not going to be an issue with the new child?"

When Hickson, now 36, gave birth to her son in December 2014, two of her other children had been removed from her home a year earlier and placed with family. An older college-aged daughter was not in the system. Hickson had tested positive for methadone during the birth of one child and had been in and out of drug treatment centers, according to the Act 33 team's review of the episode.

Caseworkers from Northeast Treatment Centers (NET), the contractor assigned to Hickson, were seeking to terminate Hickson's rights to her two other children while also providing in-house services to Hickson and her toddler son. There were ongoing domestic-violence issues with the father of the children, according to its report.

A judge deemed both parents unfit and revoked custody of the two older children in July 2016.

But as all that was going on, the caseworker assigned to Hickson made no attempts to remove the toddler from her care, the review found, even after complaints came in that the 18-month-old boy had not been to a doctor in a year and had missed three sets of vaccinations. NET closed the case, without holding a mandatory closing conference in January 2017.

To make matters worse, several required consultations with psychologists and nurses who could have identified medical issues with the child or Hickson's continued drug use and mental-health issues never occurred, the review team's report said.

Instead, the investigators found, the caseworker "focused on the mother's strengths and did not look at her history, the level of risk, or the potential safety issues."

The caseworker and the supervisor had been hired by NET in 2014 with previous experience. Both were fired after the March episode.

"This baby had a horrible thing done to him. … We do not shy away from our responsibility," said Regan Kelly, CEO of NET. "It may seem as if it's an automatic decision [to remove a child], but it's really not. It depends on the support a family has. It depends on the timeline of events."

Gulino, the medical examiner, said that in reviewing the case, the team questioned whether high case load or fatigue could have dulled the caseworker's sense of danger.

"Having to do more and more cases, you run into situations where people are more traumatized," he said. "And people are so used to seeing terrible things that their terrible-thing meter doesn't go off when it should."

Following complaints of burnout among staff on the ground, DHS recently hired more caseworkers in an attempt to limit to 10 the number of cases per worker.

Hickson sits in a Northeast Philadelphia jail, awaiting arraignment on the charges. Her family is trying to get together money to hire a lawyer.

Her mother, Deborah Hickson, still lives in the brick home where police say her daughter jumped from the window that day.

She says that her daughter was a good mother and that her other children were wrongfully taken. The stress of separation and fear of losing her youngest child, the mother said, drove her to the brink. She started hearing voices.

"She was hurt, she was so hurt," Deborah Hickson said. "She was so afraid of losing [him]. I think she just missed her kids so much, I think it was just breaking her down."

The little boy is living with family and has recovered from the fall, his grandmother and officials said.

"A lot of things went wrong here," said Gulino, who has reviewed grim narratives of child deaths and near deaths since the review team was formed in 2008. "The only good thing is the child did not die. Thank God."