Red, a 12-year-old Labrador who is retired as an active search dog, completes a training exercise on a rubble pile in Pumphrey, Maryland, August 18, 2011. Not long after American Airlines flight 77 crashed into the Pentagon on September 11, 2001, Red was at work. [Photo/Agencies]

Red, a 12-year-old Labrador who is retired as an active search dog, climbs a training ladder in the yard of her owner Heather Roche in Annapolis, Maryland, August 18, 2011. Not long after American Airlines flight 77 crashed into the Pentagon on September 11, 2001, Red was at work. [Photo/Agencies]