A Mexican national died in U.S. Customs and Border Protection custody Monday.
CBP said Tuesday it arrested the 40-year-old man for re-entering the country illegally after he was deported. Medical personnel diagnosed him with flu-like symptoms, liver failure and renal failure and transferred him to a medical center in El Paso, Texas.
The man died at the hospital later that day.
He's now the fourth migrant to die in U.S. care since December. An 8-year-old boy and a 7-year-old girl from Guatemala died in December. Both children came into the U.S. with their families. A 45-year-old Mexican national died in CBP custody in February. He had been arrested for illegal re-entry into the U.S.
The ACLU called for an investigation into the "conditions at CBP detention facilities and its medical care practices."
One CBP official said in a statement that the agency's Office of Professional Responsibility initiated a review into the most recent death. The other three deaths are all under investigation.
