"america tonight." i'm lisa fletcher for joie chen, who is on assignment. >>> in the nation's fastest growing city australian, texas where more than 100,000 have moved in, in just the last five years, the housing crisis is growing especially acute for low income residents. and now there's growing concern that the ploddest shelter they do have may be targeted for profit. "america tonight's" christof putzel explains why. >> roberto and margarita sanchez love to throw a party. it's good times like this that help keep their close knit community together. for decades, the north lamar mobile home park has been a home for many latino families most of them immigrants.