"On September 11, 2001, terrorists hijacked two planes and crashed them into the twin towers of the World Trade Center in New York City. Shortly after the towers fell, rescuers rushed in to search for survivors. To help out, they brought along hundreds of highly trained search-and-rescue dogs. Climbing over mounds of twisted metal and sharp steel beams, these heroic dogs made up the largest canine rescue operation in U.S. history. Look inside to find out more about the ways these brave canines risked their lives to serve their country when disaster struck."--P. [4] of cover.