Red, a 12-year-old Labrador who is retired as an active search dog, goes through an obstacle course during a training exercise 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. She was 18 months old and only recently certified as a rescue dog, a rookie among more veteran canines. For weeks, Red navigated the hazards of the rubble piles amid the clatter and chaos following 9/11. [Photo/Agencies]

Red, a 12-year-old Labrador who is retired as an active search dog, is rewarded by her handler after completing 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]