I remember reading (in Time Magazine, I think)that there was a great deal of water in the stair wells (from sprinklers and broken pipes) in Tower One, which made it rough going for people trying to escape. I just put it down to the waterpipes being torn apart by the planes. Don't remember hearing the same about Tower Two, though. And disabling the sprinkler system on the higher floors would ensure a very hot fire, but again, the planes probably took care of the sprinkler system very well on their own. Disabling it ahead of time, if it was done, would have been as a fail-safe in case the planes didn't do the expected damage.
And the guy leaves New York on Sept. 11. Very interesting.
Unless it is a deluge system, (wasn't) the system is only plumbed for a certain number of heads to operate. They are fusible heads. There is a OS&Y valve at the sprinkler riser that will turn off the system. The valve will be either chained open or monitored by the fire alarm panel as a supervisory signal, or both. Normal operating procedures for the FD should have been to get big lines down and to begin pumping the system. A building this high would have had boost pumps at various levels to up the pressure. Head pressure for water is considered to be 0.5 psi per foot. A single stage fire pump will make maybe 300 lbs/sq and still give a usable amount of water.
What I am saying is that #1 the system was no doubt overwhelmed in addition to being breached. #2 A person who knew what they were doing could go a long way toward making sure the fire was big.