I've heard it said that, although nobody would dispute that the 9/11 attack on the WTC was a shocking tragedy, the companies who had been using the buildings shed no tears for the actual buildings because they had been becoming increasingly problematic, having been built just at the time when computers were coming into use and consequently ill-suited to modern IT requirements and in constant need of very big, increasingly costly wiring upgrades. I read somewhere that a few days before the attack the electricity had been turned off in half of one tower, which has contributed to at least one of the conspiracy theories.