A border collie named Cowboy, a search canine for the Federal Emergency Management Agency, yelps anxiously from the top of the pile of rubble at the World Trade Center site in New York on Sept. 21, 2001. The 100 FEMA dogs certified nationally as canine search specialists "have a sense of smell so keen that they pick up scents in the tightest spots, where no equipment can go," says Don Hull, a Los Angeles fire batallion chief with FEMA. (AP Photo/Alan Diaz)