This is Staff Sergeant Chris Braman. His military history started as a cook, but with his physique he was quickly grabbed by special forces and made into an airborne special forces soldier. After being away from his family 218 days a year for a couple of years he went back to cook duty at the Pentagon. When the hijacked plane slammed into the Pentagon on 9/11, he rushed in and out of the still burning ruins, managing to carry three people out of the flames. Only one of them survived. Chris himself suffered chemical burns to his throat and lungs, as well as the mental scarring. He received the Purple Heart and the Soldier's Medal for his bravery. You can read his account here.
Although the presence of a camera appears to extinguish every trace of a smile from his face, he smiles and laughs a lot. He is 33 years old and has a family consisting of his wife and three children.