A steel column, which is being installed at the National September 11 Memorial and Museum, is believed to have come from precisely the place on the north tower, in between the 93rd and 99th floors, where a hijacked plane struck and exploded into flames more than 12 years ago.  Some at the museum say they see the outline of a woman's face near the top of the mangled artifact.  "You can see the face clear as day, as if it’s looking down over a sacred spot," one person said.  Some workers have even started referring to it as the "Angel of 9/11."