If you were on vacation with your parent and they got arrested for drunk driving. Would you be placed in the cell with your parent? No, you would be placed with a relative or a temporary foster care. Wouldn't that be traumatizing?
Most of the children were placed with family members in the US. The ones that couldn't be placed were sent to the camps. What is the alternative, put them in the holding areas with their parents or set anybody free if they are arrested with a child?