whether it can be done safely and responsibly. at exxonmobil we know the answer is yes. when we design any well, the groundwater's protected by multiple layers of steel and cement. most wells are over a mile and a half deep so there's a tremendous amount of protective rock between the fracking operation and the groundwater. natural gas is critical to our future. at exxonmobil we recognize the challenges and how important it is to do this right. >> greta: we go behind the scenes of the bush administration with dick cheney in 60 seconds. but first to our new york newsroom. >> reporter: two american hikers held in iran for more than two years could be heading home. iranian court has set bail at half a million dollars a piece. they were arrested near the iranian border and convicted ofs knowledge. the men and a third hiker claimed they mistakenly