[null and void]

How could such a large structure become fully involved in fire before sprinklers or firefighters could intervene?

Perhaps someone turned off the sprinklers. See post #22

[originalbuckeye]

Or an accelerant on each floor.

[matt04]

From what I understand in modern systems, if critical components of sprinkle systems are shut off such as pumps or main valves it triggers a “trouble” alarm in the fire panel. it will not sound the alarm and cause a evacuation, but the alarm company will get a alert that something is wrong.