With the second reported fatality of a young child in the custody of US Customs and Border Protection this month, many are raising serious questions about CBP practices, but so far officials have provided answers that are spectacularly unsatisfying. 

Congress needs to launch a thorough investigation that, if nothing else, answers this one basic question: Were the deaths of 8-year-old Felipe Gomez Alonzo on Christmas Eve and 7-year-old Jakelin Caal Maquin two weeks earlier avoidable?

To begin with, we must recognize that children fleeing Central America are among the most vulnerable children on the planet. They have lived with non-stop stress and sometimes fear. Many have witnessed terrible loss and violence in their own families. And most lived in poverty, lacking regular access to medical care -- including life-protecting preventive care, such as vaccinations.