A third explanation is less obvious but makes sense of the non-sequiturs in the above explanations: perhaps Silverstein's statement was calculated to confuse the issue of what actually happened to Building 7. By suggesting that it was demolished by the FDNY as a safety measure, it provides an alternative to the only logical explanation -- that it was rigged for demolition before the attack. The absurdity of the FDNY implementing a plan to "pull" Building 7 on the afternoon of 9/11/01 will escape most people, who neither grasp the technical complexity of engineering the controlled demolition of a skyscraper, nor its contradiction with FEMA's account of the collapse, nor the thorough illegality of such an operation. Thus the idea that officials decided to "pull" Building 7 after the attack serves as a distraction from the inescapable logic that the building's demolition was planned in advance of the attack, and was therefore part of an inside job to destroy the entire WTC complex.
Go here for full article: http://www.wtc7.net/pullit.html
Also do your own google searches for silverstein pulling building 7, this is the single best piece of evidence for me that the WTC buildings were demolished by criminal elements in the government, not by terrorists.