. >> rosalind jordan in washington. >>> ahead on al jazeera - china clamps down on hong kong, delivering a blow to pro-democracy campaigners, and we get ready for our campaign season. we look at the expensive battle for control of the u.s. senate in "the week ahead". first, on this labor day weekend we are looking back on the big stories, and begin in the rio grand valley in texas. >> i'm heidi zhou-castro, we spent a month at the center of the immigration crisis. homeland security says it's caught 63,000 children crossing into the u.s. this past year alone. >> reporter: we arrived in jooup to find a border -- june, to find a border of holes. 10,000 unaccompanied children were crossing the border. mostly from guatemala, honduras, and el salvador overwhelmed detention centers, provoking an outcry. most called the situation a humanitarian crisis, people in a few communities protested against the children's presence. the obama administration responded by deporting more migrants, and texas governor rick perry announced he would send 1,000 more troops to the border. the numbers crossing dropp