jaydeehess
Penultimate Amazing
The Con Ed was mostly in the NW quadrant. The moment frame remained coupled to the foundation there and broke loose last... the movement resulting was rotation about the NW quadrant above Con Ed. The torque / twist caused the kink as the columns connecting col 73 to the north facade held the west part from probably last floor sections to drop... those west of col 73 to the nw corner. The twist can be explained by the NE quadrant leading the collapse. Perhaps... The 2+ seconds of approximate FF acceleration tells us that the collapsing moment frame broke free at the 8th floor... just above the 2 story section of load transfer structures.
A better explanation of what I was saying above JSO.