I still don't get why people are either surprised or resort to conspiracy theories. I worked in the World Trade Center from 1997-99 (Tower 2, 37th floor) and when I arrived was given a fanny pack "escape kit" including torch, cylume stick, whistle, water bottle and several burn dressings. I am not kidding! After the car bomb in 1993 everyone in the building knew we were a target and I recall more than once looking up and wondering if some idiot would fly a plane into the damn thing. A stunningly obvious target. This was made worse by the fact that we KNEW the fire codes were deficient; because the WTC is owned by the Port Authority of New York and New Jersey it is classified as a givernment building for fire codes - hence the stairwells were KNOWN to be too narrow - they filled with smoke even in the 1993 car bombing; must have been an inferno on 9/11. Still have the useless "fanny pack" survival kit somewhere. The whistle must have been useful. (sarcastic)

"A stunningly obvious target." True. Really, most of the claims that "we never imagined" made since 9-11 are complete nonsense. You just gave one reason this is so. There are others. For instance, I first worked in Washington in the Spring of ...think it was 1974. Even then, it was widely known that there was at least one SAM missile detachment on the top of a building adjacent to the White House. They weren't guarding against the threat of falling pigeons. Israel had more than one incident with a (small) aircraft crossing their airspace without permission, leading to military intercepts. The threat that a plane would be flown into a building in Tel Aviv was widely discussed in many places, including American papers, after each incident. For that matter, Tom Clancy actually wrote a novel in which a major plot point was a Japanese civilian pilot flying a large airliner into the Capitol, killing most of Congress. "No one imagined"? Bullcrap....