serge of children crossing the united states border. thousands and thousands of them are winding up in detention. the homeland security secretary went to arizona today to get a firsthand look at the problem. we have an update. >> this is the second visit to the southwest border in less than a week. today he toured a detention facility housing some of the thousands of undocumented families. >> reporter: the brush along the southern border, it's the front line of an urgent crisis. since october tens of thousands of unaccompanied children and families have poured over the rio grand and into the cuss day of border protection. >> next year more than 150,000 unaccompanied children may attempt to cross our borders. this is a crisis. it's a crisis that's been in the making for years. one that we should have seen coming. a few concrete actions have been