Three workers with the Mississippi Department of Child Protective Services were terminated Friday, WLBT-TV reports, after an investigation into the agency’s prior reports of abuse in a case that ultimately led to the death of a 4-year-old Natchez girl.

Armani Hill died of injuries police say she sustained at the hands of her mother’s boyfriend, James Christopher Anderson. The 24-year-old Anderson is charged felony child abuse against Armani and her 3-year-old sister, who was badly injured, but survived.

The children’s mother, Lakeisha Marie Jones, is charged with child deprivation. Investigators said she knew Anderson was abusing her children and failed to stop him.

Natchez Police Chief Walter Armstrong said during the investigation, police learned the Child Protective Services had been contacted by the Natchez-Adams School District and opened two cases for the children due to previous injuries before the incident Wednesday and both cases were closed just before the deadly incident.

Armani’s death caused the state to open an investigation into how the previous allegations of abuse were conducted. The result of that investigation appears to have led to the termination of the three workers.