Construction workers place concrete formwork for a wall on the second floor of the Pentagon. Construction workers place concrete formwork for a wall on the second floor of the C-ring of the Pentagon on Feb. 12, 2002. Crews are working nearly around-the-clock as they pour concrete for floors and walls to replace those damaged in the Sept. 11, 2001, terrorist attack on the building. SHARE: Download: Full Size (0.1 MB) Credit: VIRIN: 106197-S-XNI79-766.jpg Photo Gallery