In this alternate scenario, for six to ten years, latitudes as far down south as Chicago experience eight to nine months where the daily high barely reaches zero Fahrenheit (−18 degrees Celsius).
The steel of the skyscrapers in this alternate scenario is also different, with carbon consisting of 2.5% of the overall composition.
Now the question is, how does steel react to ice? Does it rust? Crack? Harden? Or something else? And how would a decade of endless cold affect the skyscraper in a preferable Life After People?