Effects were similar, but instead of needing any explosives, the fire would have been enough to weaken the steel supporting the massive weight of building above it, thus the pancake effect.
WTC 7 seemed strange to me, though, with neither aircraft impact nor fire to weaken structural elements.
Maybe someone can explain that one to me.
I;m no 'troofer', but I am curious.
Effects were similar...
The only similarity was the obvious effect of gravity. Other than that, it didn't look anything like a controlled demolition as far as I'm concerned...
In one of the basements of 7 WTC were the fuel tanks for the emergency generators for the entire WTC. This fuel burned all day long (and for several days afterward) leading to the colapse of the building.
From 9/11 Myths—By Popular Mechanics Pages 53-54
“The collapse of WTC 7 was initially puzzling to investigators, but they now believe the building failed from a combination of long burning fires in its interior and damage caused by debris from the North Tower's collapse. This conclusion is a modification of initial findings from FEMA, reached in a preliminary report released in May 2002, that attributed the collapse almost exclusively to the fires. The report stated there was relatively light structural damage prior to the building's collapse.
Page: 55:
NIST’s analysis suggests the fall of WTC 7 was an example of “progressive collapse” a process in which the failure of parts of a structure ultimately creates strains that cause the entire building to come down.
Video footage of the fall of WTC 7 shows a crack, or kink, in the buildings facade just before the two penthouses disappared into the structure, one after the other. The entire building fell in on itself, with the slumping east side of the structure pulling down the west side in diagonal collapse.
Page 55 goes on after that describing the unusual construction of the building. This is a very informative book and I suggest everyone reads it. The building was on fire inside. They think it was due to the broken gas lines in the basement of the building. It posed such a danger to the firefighters, they were pulled out and the building was left to fall.