Well, I haven't studied the question in depth. The question was originally posed by someone whose depth of insight (ability to see patterns in depth over time) is remarkable. I think the some of the answers might be found in the parallels that pertain to the ability of people to escape: in one case, locked doors, and in another, an announcement that all was safe and people should stay put. Additionally, most WTC deaths occurred among those who worked above the impact zone. (If the terrorists wished to maximize death, why didn't they target the 30th or 40th floors?)
Quotes from the Triangle Fire web site:
"The tragedy still dwells in the collective memory of the nation... "
"The images of death were seared deeply in their mind's eyes."
"In the weeks that followed, the grieving city i... reeled in numbed grief at the atrocity that could have been averted with a few precautions."
"Outraged cries calling for action ... could be heard from every quarter..."
Other answers might be found in the way the court cases and inquiries were handled ( "Blame shifted..." building inspectors were called in... ), and the fact that significant long-term preventive or social change did not emanate from them. Sweatshops exist throughout the world and even in the US today, and fire safety issues related to emergeny egress plagued the country for a long time (Coconut Grove and a fire in Kentucky across the Ohio River from Cincicnnatti come to mind). Both the process and the publicity were managed so as to divert attention and inquiry, and there is a question as to whether justice was served.
That's what I can see at a quick glance...
I'm sure there's more.
Why don't you register over here
(
http://www.solariactionnetwork.com/phpBB2/viewforum.php?f=47 )
and ask Catherine Austin Fitts for an explanation as to what she meant when she said "the design of 9/11 appears to draw on the success of the Triangle Fire".