An unaccompanied minor died in U.S. government custody in Texas on Tuesday, Buzzfeed News reports. According to border officials, the 16-year-old migrant boy died after suddenly becoming “noticeably ill.” Evelyn Stauffer, a Health and Human Services spokesperson, said the boy showed no health concerns when he was put in the custody of the Office of Refugee Resettlement, but complained of a fever, chills, and headache the morning after he was transferred. The boy was moved to an ORR shelter by Immigration and Customs Enforcement officials on April 20. The next day, April 21, the boy was brought to a hospital where he was treated and released back to the shelter later that same day.

“The minor’s health did not improve after being transferred back to the shelter so on the morning of April 22, 2019, the minor was taken to another hospital emergency department via ambulance,” Stauffer said. “Later that day, the minor was transferred to a children’s hospital in Texas and was treated for several days in the hospital’s intensive care unit.” The boy died about a week later on April 30. The death is under investigation by ORR.