The trump administration doesn't know how many families were separated at the border when it implemented its zero tolerance policy. and they still don't know just how many families have been reunited. a new homeland security inspector general shows widespread errors prevented officials from being able to properly collect and track the data. cnn's natasha chen is following this story for us. natasha, what were these errors, and will the government be able to find and reunite these families? >> well, ana, a lot of these errors point to software problems and the systems from different agencies no...