Illegal immigrants prepare to enter a bus after being processed at Tucson Sector U.S. Border Patrol Headquarters Thursday, Aug. 9, 2012, in Tucson, Ariz. The U.S. government has halted flights home for Mexicans caught entering the country illegally in the deadly summer heat of Arizona’s deserts, a money-saving move that ends a seven-year experiment that cost taxpayers nearly $100 million.(AP Photo/Ross D. Franklin)