Federal officials revealed a 9-year-old girl from Mexico drowned earlier this month as she attempted to cross the Rio Grande river into the U.S. The girl’s mother, who is Guatemalan, and her 3-year-old brother were also found unresponsive but were able to be resuscitated.

This comes as more than 18,000 unaccompanied migrant children are now in U.S. custody, according to the latest figures. Over 5,000 of those are in Customs and Border Protection facilities, which are not equipped to care for children.