On Sunday, NewsHour Weekend examines the lack of diversity in the tech industry. The giants of Silicon Valley -- Google, Twitter, Facebook -- report that just three to four percent of their workforce is black or Hispanic, and men outnumber women by more than two to one. Now, tech companies are investing hundreds of millions of dollars to address the imbalance. In New York, one camp is training such a new generation of software coders. NewsHour Special Correspondent Karla Murthy reports.