Arielle is 15; her brother is 13. For the past five months, they've been living in a truck with their father, Tom. He is an out-of-work carpenter in Florida's Seminole County, where one-third of America's homeless families live.

Pelley described how Arielle and Austin eat their meals out of cans, bathe in gas station bathrooms and spend their evenings in libraries -- not just for the computers but also for the lights.