I notice that there was nothing in that video that supported the "concrete core" theory.
thanks for finding this gem.
NARRATOR: Before signing off on the design, Robertson and his team performed one last unprecedented safety check.
Leslie Robertson: One of my jobs was to look at all of the possible events that might take place in a highrise building. And of course there had been in New York two incidences of aircraft impact, the most famous one of course being on the Empire State Building. Now, we were looking at an aircraft not unlike the Mitchell bomber that ran into the Empire State Building. We were looking at aircraft that was lost in the fog, trying to land. It was a low-flying, slow-flying 707, which was the largest aircraft of its time. And so we made calculations, not anywhere near the level of sophistication that we could today. But inside of our ability, we made calculations of what happened when the airplane goes in and it takes out a huge section of the outside wall of the building. And we concluded that it would stand. It would suffer but it would stand. And the outside wall would have a big hole in it, and the building would be in place. What we didn't look at is what happens to all that fuel. And perhaps we could be faulted for that, for not doing so. But for whatever reason we didn't look at that question of what would happen to the fuel.