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The atrium was designed with three walkways crossing over it. The second walkway was directly beneath the fourth floor walkway and the third floor walkway was offset. All walkways were hung from the roof with long, steel hanger rods. The original design called for the third floor walkway to be on its own set of hanger rods while the second and fourth floor walkways would be fastened to the same, very long rod. The design change called for two rods holding the second and fourth floor walkways. This change would have been fine if only someone would have noticed that the load on the connection of the rod to the fourth floor walkway beam was doubled. All that needed to be done was to put a larger washer in place to distribute the load across a greater area of the beam.
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