The minor and her family were being held at a facility in the city of Harlingen, close to the Mexican border, Customs and Border Protection said in a statement.
“Emergency Medical Services were called to the station and transported her to the local hospital where she was pronounced dead,” the statement said, adding that the Office of Professional Responsibility would conduct a probe as it standard protocol in the case of a death.
The agency stressed it had contacted the Department of Homeland Security’s Office of Inspector General and the Harlingen Police Department about the incident.
The death comes just days after a 17-year-old unaccompanied migrant from Honduras died at a facility run by the Department of Health and Human Services’ Office of Refugee Resettlement in Florida. The Honduran government named him as Ángel Eduardo Maradiaga Espinoza and called for a full investigation and a criminal investigation if any wrongdoing is found.