"The investigation into the tragedy revealed that, in addition to the not well thought out fifth floor addition, the badly placed air conditioning units, and reducing the diameter and number of support columns, the collapse was a perfect storm of terrible engineering. Had the developers stuck to the original plans, the stucture would have been twice as strong as it needed to be. Given all of the errors, it was amazing that the structure had had stood for 6 years."
January 1, 1970
https://en.wikiquote.org/wiki/Sampoong_Department_Store_collapse