This close-up photograph shows damage caused by the right wing, before the collapse.
The plane’s right wing appears to have hit the solid concrete slab that forms the second floor of the building between columns 18 and 19, severely deforming it. The bottom part of column 19 on the second floor has been displaced by the wing’s impact.
The façade on column 20 on the second floor has been destroyed, marking the boundary of the severe damage caused by the right wing. The façade on column 21 on the second floor remains intact. (U.S. Marine Corps/image enhancement by Pentagon Building Performance Study Team)