The U.S. government acknowledged Wednesday that an unaccompanied 10-year-old girl from El Salvador died in custody last September, CBS News reports, the sixth known minor in the past eight months to die in government custody or shortly after being released. The young girl’s death had not previously been publicly disclosed, as the government is only required by law to notify local child welfare authorities, but the timing of her death makes her the first unaccompanied minor fatality in U.S. custody since 2010, according to the Department of Homeland Security.

The Department of Health and Human Services is responsible for the care of unaccompanied minors that come across the border, and according to a HHS spokesperson the girl was in a “medically fragile” state with a medical history of congenital heart defects when she entered an Office of Refugee Resettlement facility in San Antonio on March 4, 2018. “Following a surgical procedure, complications left the child in a comatose state. She was transported to a nursing facility in Phoenix, Arizona for palliative care in May after release from a San Antonio hospital,” a DHS spokesperson said. “On September 26, she was transferred to an Omaha, Neb., nursing facility to be closer to her family. On September 29, the child was transported to Children’s Hospital of Omaha where she passed due to fever and respiratory distress.”

“On Monday, a 16-year-old boy died at a Border Patrol station in Weslaco, Texas. A Border Patrol official said Monday that the boy, Carlos Hernandez Vásquez, was brought there the day before, after he told personnel at the McAllen, Texas immigrant processing center that he felt sick,” CBS News reports. “The four other deaths in U.S. government custody occurred among children either detained by Border Patrol, or released by the agency to a hospital.”