For decades Americans have worried about our dependence on foreign oil and gas. By 2005 we were importing 60% of our energy, but in 2008 a new technology called horizontal hydrologic fracturing or “fracking” raised the promise of energy independence. U.S. crude production is up 50% and imports have fallen 35%. But getting oil from a massive shale deposit in North Dakota to refineries is raising serious concerns about public safety. Sandy Hausman has more on that story.