[Arthalion]

Actually there are engineers who now believe that the fire supression system in the north tower, the first to be hit, was working perfectly. I was listening to a couple guys on TV discussing how the water mains for the towers were tied together, and how that one minor design problem may have destroyed the towers. Apparently, the builders of the tower never envisioned a scenario where both towers contained raging fires, so there was neither sufficient capacity or pressure to run the fire sprinklers on multiple floors in both towers simultaneously. After the north tower was hit, fire was burning in about 15 different floors...which was about all the WTC fire system was capable of handling. They noted that the fire did NOT appear to be spreading at that time, and that there was evidence of steam coming from the burning floors which indicated that the system was at least partially functioning.

The towers fate was sealed when the second jet hit the second tower. There wasn't enough capacity or pressure to spray another 15-20 burning floors in the second tower, so when those systems activated, both towers lost water pressure. This is evidenced by the fact that the fire in the north tower began spreading almost immediately after the other tower was hit, and the fact that the steam plumes stopped showing up in the photos and videos.

[Rome2000]

I don't know about the accuracy of that report.

From what I remember, each tower supposedly had gravity tanks on the top for supressing fires on the upper floors, as pumping water from the ground floor under any circumstances would not constitute a reliable fire protection system.

Each building would have had separate fire pumps to service the lower to mid tower floors, and they should have not been affected by the initial attack.

I understand that NFPA has prepared a preliminary report on the incident but for some strange reason it has been deleted from their website, probably for security reasons.