CBS News reported Wednesday that a 10-year-old girl from El Salvador died in a facility run by the Office of Refugee Resettlement (ORR) in September. She was the first of six migrant children to die in U.S. custody, in a hospital, or shortly after being released, in the last eight months, but the government didn’t acknowledge her death until Wednesday. Her name has not been released.

Mark Weber, spokesman for the Department of Health and Human Services, which oversees ORR, told CBS News that the girl was “medically fragile” due to a congenital heart condition she had prior to entering U.S. custody in Texas. “She passed due to fever and respiratory distress” after being treated in multiple facilities, including a San Antonio hospital, a nursing facility in Phoenix and a children’s hospital in Omaha, Neb., Weber said,

The girl was the first migrant minor to die in U.S. custody since 2010, ORR and Department of Homeland Security officials told CBS. On Monday, 16-year-old Carlos Hernandez Vazquez died in a U.S. Customs and Border Protection (CBP) shelter in Weslaco, Texas. Hernandez was from Guatemala, as were the four other children whose deaths were previously reported.

Vazquez’s death “has renewed national attention and outrage from December, when two young children died in CBP custody in three weeks,” Dara Lind writes in Vox. “It’s becoming increasingly clear that the government is in the midst of a broader public health crisis regarding migrants, especially children, in its care.”

Minors, Lind explains, are generally supposed to be held in Border Patrol facilities for less than 72 hours before being transferred to ORR or to U.S. Immigration and Customs Enforcement. Vazquez was held for six days. The other children who died were held for varying lengths of time. Some died—from ailments ranging from a severe brain infection to pneumonia—while in the hospital or in custody, others after being released.

The facility in McAllen, where Vazquez died, is in the middle of a flu outbreak, leaving current occupants essentially quarantined. The situation has become so dire that officials have suspended intake. Prior to the quarantine, that shelter, Lind writes, was “held up as a model for what CBP wants to build more of.” Now, she says, “CBP is essentially improvising.”

Chair of the Congressional Hispanic Caucus Rep. Joaquin Castro, D-Texas, believes the Trump administration may have covered up the death of the 10-year-old who died in September.

“I have not seen any indication that the Trump administration disclosed the death of this young girl to the public or even to Congress,” he told CBS News. “If that’s the case, they covered up her death for eight months, even though we were actively asking the question about whether any child had died or been seriously injured.”