On Dec 16, 12:09*pm, Chicago Paddling-Fishing wrote:
When is the last time there was a fire in a highrise
that was allowed to burn for 7 hours because the firefighters didn't have
access to water because another building collapsed and severed the water
supply?

The closest related instance I can come up with is One Meridian Plaza
in Philadelphia in 1991. A smoke detector triggered at about 10:23 on
Feb 23, 1991 on the 22nd floor. The fire burned through electrical
cables as fire crews reached the 11th floor. All equipment had to be
hand carried up 20 floors using only battery powered lights.

Almost from the beginning, there were water supply problems, and
firefighters had inadequate pressure and water flow to attack the fire
as it spread upward to the 23rd and 24th floors. It wasn't until 2:15
a.m. that they managed to get a 5" line up one of the stairways. By 6
a.m. they'd gotten a third as far as the 17th floor when a sprinkler
contractor adjusted pressure reducing valves on the standpipes to give
firefighters near normal flows. By then, however, the fire had spread
upward and could no longer be fought with manual hose systems.

All firefighting operations were stopped shortly thereafter and the
building evacuated at 7 a.m. due to the danger of a pancake collapse;
and the fire burned unimpeded for another several hours. When the
fire reached the 30th floor, it was supressed by automatic sprinklers
that were being supplied by fire department pumpers. It was declared
under control at 3:01 on the Feb. 24th, about 17 hours after starting.

CT folks often cite this fire as an example of a serious fire in a
high rise, but as one that burned longer and still did not cause the
same failure as the WTC fires. The flaw in that logic is two-fold.
Firstly, the fire did not burn any longer on any one floor than WTC.
It simply consumed all flammable materials and moved upward.
Secondly, the fire at One Meridian had only 8 floors above the damage
zone, not the 20 or more at WTC. That's a significant difference in
supported loads where the structural factor of safety is concerned.

The photos of the damage at One Meridian show exactly what engineers
would expect from such an event. The fire seriously twisted and
deformed floor joists and beams, but the structure stayed up because
the columns were not sufficiently damaged or displaced to cause
buckling.

If you're into such stuff, here's the report from the US Fire
Administration:
http://www.usfa.dhs.gov/downloads/pd...ons/tr-049.pdf

Joe F.