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.