The child died after experiencing "a medical emergency," authorities said.
An 8-year-old girl died while under U.S. Border Patrol custody in Texas on Wednesday, authorities said.
The child and her family were in custody at the Border Patrol station in Harlingen, near the border with Mexico, where she had "a medical emergency," according to a statement from U.S. Customs and Border Protection (CBP), the Border Patrol's parent agency.
The girl was rushed to a nearby hospital where she was pronounced dead, CBP said.
The CBP's Office of Professional Responsibility, charged with upholding the agency's ethical standards, is conducting an investigation into the incident, as is protocol. The U.S. Department of Homeland Security's Office of Inspector General and the Harlingen Police Department were also notified.
CBP did not disclose the girl's nationality or provide further information about her death.
News of the child migrant's death comes amid concerns of a looming surge at the border now that Title 42 pandemic-era restrictions have expired.
The incident occurred amid concerns of a looming surge at the U.S.-Mexico border now that so-called Title 42 restrictions have expired. The pandemic-related immigration policy allowed the United States to swiftly turn back asylum seekers at its border with Mexico for the last three years in the name of protecting public health.
Last week, a 17-year-old Honduran boy traveling alone died while under U.S. Health and Human Services Department custody in Safety Harbor, Florida.