The attacks were intended to bring both buildings down within minutes if not seconds. That would have resulted in the deaths of over 100K. Those in the buildings and the surrounding buildings and area. Two reasons to be thankful. The planes hit high and the towers were marvelously constructed. Designed in 1967 to survive a strike by a Boeing 707 doing 400knots. Unfortunately only impact, not resulting fire and hear had been prepared for.
In the same manner, the 93 bombing had been designed to bring down the one tower immediately. Killing 50K and Bubba treated it as a criminal enterprise, no more important than a bank robbery.
Other than Osama bin Laden, I consider Bill Clinton responsible for 9/11. He did NOTHING to combat terrorism throughout his terms.
Oh yeah, and after the bombing of the Cole, he sent FBI agents to Yemen to investigate. WTF?!