There is no case that has shocked New York City more in the past year than that of five teenagers who were accused of attacking and sexually assaulting an 18-year-old woman at a park in the Brownsville section of Brooklyn in January. Neighbors were outraged at the event and the fact that it took police a couple of days to even make it public. The alleged attack was seen as a failure of the police to keep the community safe, and perhaps even a failure of elected officials to ensure that the public is kept informed—but now it appears to be a case of something entirely different.

Prosecutors dropped the rape charges against the boys late last week, noting that whatever took place seemed as if it was consensual, and investigators were looking into the possibility of sexual contact between the woman and her father. There were, for better or worse, cell phone videos of some of the incident, and the woman apparently gave very inconsistent testimony and expressed unwillingness to go forward with the case. “That night, this young woman’s father and the five young men engaged in conduct that was reprehensible and wrong, but because of the lack of reliable evidence, criminal charges simply cannot be sustained,” Brooklyn District Attorney Ken Thompson said in a statement.

Rather than a failure of law enforcement, this case is a microcosm of the effects of the disintegration of the family in the past 40 years. According to the New York Times, the woman in question had a turbulent family history:

She was taken from her mother, a drug user, at 2 and placed in the care of a local family, who later moved to California. The woman was eventually removed from that family, the officials said. Afterward, she had lived in a series of group homes and other facilities. Investigators learned she had a history of emotional troubles, the officials said.

When she turned 18, the woman, whose mother had died, learned her biological father’s identity and contacted him through Facebook, the officials said. Last July, she came to New York to meet him.

Drugs, absent fathers, girls who don’t know appropriate sexual boundaries, boys who have no guidance about behavior, the failures of the foster care system—all of these factors have culminated in this terrible incident. We don’t know a lot about the teen boys here, except to note that in the case of two of the teens, at least, it was their mothers bringing them to the police station, not their fathers.

While there is not much that police or prosecutors or the mayor might have done to prevent it, we might look back at this woman’s life and see a tragic pattern.

In a 1999 report to Congress, the U.S. Department of Health and Human Services reported that between one-third and two-thirds of child maltreatment cases were affected by substance use. According to data in the Adoption and Foster Care Analysis and Reporting System (AFCARS), for almost 31 percent of all children placed in foster care in 2012, parental alcohol or drug use was the documented reason for removal.

The problems faced by children in foster care are often insurmountable. The effects of the abuse and neglect they have experienced before entering the system are hard to counteract. But there is also a widespread sense that the foster care system is broken.

In 2014, three private foster agencies in New York paid $17.5 million to settle a suit with eight people who claimed they were abused, starved, and imprisoned by a woman who fraudulently fostered at least 22 children and adopted 11 of them. The city of New York paid almost $10 million to those eight victims and two others because the Administration for Children’s Services failed to oversee their cases properly. A group called Children’s Rights has filed lawsuits in almost half the states in the country, alleging that foster care systems are failing to protect the rights of children.

There are more than 400,000 children in foster care, and they represent only a fraction of the children whose lives have been upended and in some cases destroyed by the breakdown of the American family. But if we’re trying to do better by our children, helping those in the foster care system is surely a good place to start.