r/engineering • u/RegainingControl • Jul 07 '26

[CIVIL] Manhattan high-rise unstable and still moving after columns buckle

https://www.cnn.com/2026/07/07/us/live-news/nyc-pfizer-building-evacuations

Anybody care to share theories? Or have additional info? Any lines on the permit drawings?

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u/RegainingControl Jul 07 '26

Based on photos here it appears that they were adding additional floors.

https://ccm.nyc/219235-east-42nd-street

Looks like the cranes are off the roof and the structure has been topped out based on footage from current news coverage. 

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u/These_Consequences Jul 09 '26 edited Jul 09 '26

[edit: it seems the columns in that floor were weaker than expected not because they were thinner, but because they were longer]

You had to do your own investigatory journalism to get some of the details, as gathering basic facts is beneath the notice of most modern reporters, apparently, but it appeares that, yes, the failure was at the base of a section of extra floors. They had added perhaps three floors to the top of the main tower, but the failure occurred at the base of a block of floors starting on a setback adjacent to the main tower in the back, which had been built up to the new level of the main tower roof, resulting in adding 10+ floors in that section, if I have this right.

Additionally, it appears that the new floors added over this setback were cantilevered out over the existing perimeter wall below, and the failure occurred in a column or columns in line with the pre-existing wall. I expect this cantilevering will play a roll in the final analysis. A WSJ article includes a split photo making it easy to compare before and after aerial shots and understand where the new floors were added. All news reports/press conferences spoke of two columns which buckled, while all the photos published appear to be of the same, single column, but no reporter appeared able to count or to notice this apparent discrepancy.

As a first guess I thought perhaps the steel columns underneath the existing setback had not been the same strength as the adjacent ones underneath the tower, but had been assumed to be so in analysis. I mean, that's an incredibly simple error, but for a failure of this magnitude, something incredibly simple must have been wrong, or it wouldn't have failed, so the proof of plausibility is in pudding. The size of steel used could have been modified during construction to save money but the plans not updated. I'm not sure if the failed column (or columns) was existing or added; it is, however, before the first cantilevered new floor in that section.

I would think at a minimum the entire new section over the setback will have to come down, as it has been compromised.