In this photo taken July 20, 2011, wavy train tracks are seen in Waterloo, Neb. Triple-digit temperatures across the Midwest are stressing the region's infrastructure. The heat has been blamed for ... more 
In this photo taken July 20, 2011, wavy train tracks are seen in Waterloo, Neb. Triple-digit temperatures across the Midwest are stressing the region's infrastructure. The heat has been blamed for buckling roads from Oklahoma to Minnesota, and Union Pacific Railroad says the heat has affected its operations across its entire northern division, forcing trains to slow by 10 to 20 mph as the stifling heat threatens to kink the operation's metal tracks. (AP Photo/Nati Harnik) less 
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Associated Press | Photo By Nati Harnik
Thu, Jul 21, 2011 1:58 PM EDT