That picture makes me teary and my chest swell with pride at the same time. I got an email once that laid out the requirements to be chosen to guard the tomb, and exactly what they do and how long they do it-it was really astounding.
The 3rd Infantry Regiment posted... this message: 'The Sentinels at the Tomb of the Unknown Soldier maintain their vigil even as Hurricane Sandy bears down on the Eastern Seaboard. The Old Guard has guarded the tomb every minute of every day since April 6, 1948. Today will be no exception.'