so what what happened to the core ?
What happened to the core...
Do you understand that structures are designed with INDIVIDUAL components to function as one component?
That if one component fails, the work that the failed component was responsible for is then transfered to the remaining components?
Did the perimeter columns help support any of the gravity load of the towers?
When the plane smashed through the perimeter columns and removed those columns, the load that those particular columns were responsible for moved to the other columns.
The fires further weakened the columns which are already under stress. The core eventually came to a point where it couldn't support the load and failed. Once that started, what was supposed to stop the upper structure from coming down?
Again, were those floor truss supports supposed to do that? That "block" coming down, basically ripped connections apart. What do you think would failed first under stress? The column itself or a weaker connection attached to the column?
You can see in any video as the debris fell down the center of the towers, you can see sections of perimeter walls getting pushed outward after the floor connections were severed.
Don't forget the heavy elevator motors and electrical panels in the core.
Why do you think this photo shows a still standing core with no floors around it?
The floors were ripped away.