Name:   MrHodja - Subject:   World Trade Center Date:   11/8/2015 9:49:00 PM (updated 11/8/2015 9:55:42 PM)

While in the Big Apple today my wife and i visited Ground Zero and the 9/11 Museum.

First, my hat is off to those who designed and built the museum.  it is a very thoughtful, powerful experience, especially walking around what is left of the very underpinnings that supported those massive structures.  Eight inch thick blocks of steel mounted atop two foot tall i-beams made of two inch thick steel, encased in concrete atop solid bedrock.  The supporting steel columns were two foot square beams made of at least two inch thick steel (estimate, as we couldn't reall get close enough to measure them is we had brought a tape measure.). There also is a gallery of 8x10 photos of the almost 3,000 who perished that day.  Seeing those pictures puts a very personal touch to what could otherwise be an impersonal event.  And there are many other displays and artifacts that make the visit a very sobering and sometimes emotional event.

But to the reason for this post.  There are some who doubt the authenticity of published accounts from that day, and some who claim that the way the towers fell prove it had to be some kind of inside job.  That controversy was far from my mind as we went through the displays, but there was a narrator giving various facts to a group of folks who said the following. i will paraphrase because i didn't get a recording.  What she said was that the building was constructed one floor at a time, with extremely strong outer beams with which metal trays (my description, because i don't remember her exact words) were filled with concrete to form the floor, and after hardening each floor then became self-supporting, tied to those outside weight bearing beams.  What i do remember is her statement that 70% of the weight of each floor was born by the exterior beams.  Thus, when the heat of the fires caused by massive amounts of jet fuel caused the floors to sag, then collapse, the poorly supported centers actually pulled the exterior support beams toward the center, thus the buildings collapsed within a very narrow footprint.  i believe in a previous post one of our forum members described that construction method and what we heard today supports his or her description.

i highly recommend anyone who visits NYC try to make time to go.  As events in a country's history go, 9/11 was huge.  Those in charge have done a great job of preserving and presenting what remains in a way that helps us remember what happened there.