FALSE! They were designed to handle the impact of multiple airline impacts!
Pancake THEORY? Floors may have pancaked because their was a gap between each one,BUT, a solid reinforced concrete CORE cant collapse because their is no “space between” to start the inertia effect. Reinforced concrete is the strongest construction available & has a very high compresive strength. Notice how diggers with large “jack-hammer” attachments take weeks to demolish smaller concrete structures, slowly making each piece smaller & smaller.

However, if you look at footage of Sth Tower falling, the top 20storeys are leaning at a 15deg angle,above impact point like a tree being felled.Suddenly, this huge still intact mass , “vapourise’s” into a cloud of dust. If pancaked, what causes the “roof” level to collapse & fall?
What happens to the 100ft STEEL antennae tower? It dissappears! Where? By physics it should have fallen into the building on opposite side of street…..

Building No 7? No plane hit this at all! Duralium planes do not BRING DOWN concrete & steel structures. Office fires do not melt steel & concrete. CONCRETE does not vapourize into dust by being dropped> it has to be Mechanically pulverised by jackhammer, drill, or diamond blade saw, OR explosive force! Even after a bldg is demolished by explosives(dropped), it takes weeks to then pulverize the concrete rubble with large jackhammers!
If Pancaked, Ground Zero would have been at least 10storeys high of concrete pieces!