The WTC trusses (shown above) spanned 60' and 35' between the inner core and perimeter

storeys from the top of the building meaning the inner core supported only 6

descending core would have sheared off all bolts connecting trusses to the inner core. This would have resulted

mast of WTC 1] fell suggests it was failure of the inner core that began the

Core of WTC 1 Failed Below the Third Floor World Trade Center inner core construction photo: The

failure of trusses connecting the perimeter walls to the inner core as dictated by