Having no context whatsoever, I can only guess you're a conspiracy theorist of some sort and believe the building (and by extension, the Towers themselves) was deliberately demolished?

It might be instructive to read the following:

'In the PBS documentary America Rebuilds, which aired in September 2002, Larry Silverstein, the owner of 7 WTC and leaseholder and insurance policy holder for the remainder of the WTC complex, recalled a discussion with the fire department in which doubts about containing the fires were expressed. Silverstein recalled saying, "We've had such terrible loss of life, maybe the smartest thing to do is pull it". "They made that decision to pull", he recalled, "and we watched the building collapse." Silverstein issued a statement that it was the firefighting team, not the building, that was to be pulled, contradicting theorists' allegation that "pull" was used in a demolition-related sense.'

[en.wikipedia.org]