LAS CRUCES, N.M. (AP) — A 7-year-old girl who crossed the U.S.-Mexico border with her father last week died after being taken into the custody of the U.S. Border Patrol, federal immigration authorities confirmed Thursday.

The Washington Post reports the girl died of dehydration and shock more than eight hours after she was arrested by agents near Lordsburg, New Mexico. The girl was from Guatemala and was traveling with a group of 163 people who approached agents to turn themselves in on Dec. 6.

It's unknown what happened to the girl during the eight hours before she started having seizures and...