Video: B-Roll Tomb of the Unknowns Preservation
B-Roll of the Tomb of the Unknowns Preservation. Since 1931, the monument at the Tomb of the Unknowns has served as the centerpiece of America's most hallowed ground. In this historic cemetery, which bears witness to the military service and sacrifice of men and women in uniform throughout the nation's history, engineers, scientists and conservationists are working to protect and preserve a national treasure due to cracks that continue to get larger over the years. For three nights preservationists will work to restore the Tomb of the Unknowns filling in the cracks with a specially mixed grout to keep water from getting into them and causing the cracks to get larger. Produced by Patrick Bloodgood. Also available in high definition.