If the facia, what you saw as those looming grids from after shots at the site, had been attached every two feet instead of every three feet, the buildings might have stood another 45 min.-hr. The facings were not more concentrated because architects and builders were always very conscious of the towers’ weight.

All the elevators and stairwells were centered in the towers, so that when the planes struck and fires started, the tower centers were open enough to act as chimney flues?more realistically, blast furnaces–accelerating the fires and temperatures and stopping evacuations. Only one tower, I think North, had an isolated stairway along an outside wall, but few people knew of it or used it.

The NYFD, carrying up to 80 pounds of equipment, charged as high as the 79th floor in the South Tower before being given evacuation orders, which most never heard because communications didn’t work well inside the buildings.

The structures were designed to implode so that their 1/4-mile height did not fall over and take out blocks of downtown NYC. No one knew if the plan would really work, but it did.

9/11 bears the marks of amateurish planning, which was here a good thing. For maximum damage, the towers should have been struck around 11 am and close to their bases. The two structures usually had up to 50,000 people in each at full capacity. 1000s were saved who were late to work or were not scheduled to start until 10 am or after.

Of those who had been in the buildings in 1993, most evacuated immediately and successfully survived. People who had not experienced the earlier attack or listened to an anomalous announcement after the South Tower was hit that all was well and they should ignore any disruption did not survive as well and those on floors above the plane struck were virtually walled off by fire and destruction.

The worst of gov?t involvement is that the planes out of Boston were missing for nearly an hour on anyone?s radar, and altho? jets were scrambled out of CT, they were always far behind the commercial carriers. The question of whether or not they would shoot down civilian airlines out of the air over the Hudson remains moot.

Most of the above comes from a huge cover article in the NYT in 2002, one of the now slimey news rags best.