When did building 7 fall?

Answer 1

A controlled demolition, probably.

Scientists have found unreacted thermitic materials in the dust from the World Trade Centers, and the results have been published in a peer reviewed scientific journal. This, along with many other lines of evidence (including other essays published in peer reviewed journals) confirms that the collapses were demolitions. For further information Google: "thermitic materials 911" or visit the journal for 911 truth and justice.

Answer 2

They collapsed owing to structural failure, following a passenger jet being purposly rammed into each of them. The intense heat caused by jet fuel igniting, weakend the structural steel both inside and outside of the buildings.

Answer 3

There is no scientific evidence at all that any planes destroyed any buildings on 9/11 2001. There is extensive video evidence that two Boeing 767 jetliners hit WTC 1 and WTC 2. These impacts caused some damage to the building. The resulting fires from the burning jet fuel caused further damage to the building. Again there is no evidence that this damage was enough to cause the buildings to fall the way they did. The NIST reports on the Twin Towers deals only with collapse initiation and not the total destruction of the buildings. Instead they refer to a purely theoretical paper (Bazant/Zhou) that also has no scientific evidence to support it.

See:

http://www.foreignpolicyjournal.com/2012/09/10/911-pseudo-science-a-us-foreign-policy-built-on-fraud/

WTC 7 was hit by no planes. The south side of WTC 7 sustained slight damage from falling debris from WTC 1 (the North Tower). As the NIST WTC 7 report concluded this damage had no bearing on the buildings collapse.

The only valid scientific explanation for the three tower falls is that all three buildings fell as a result of controlled demolition.

See:

http://www.foreignpolicyjournal.com/2011/02/14/a-scientific-theory-of-the-wtc-7-collapse/

Answer 4

Controlled demolition to destroy the evidence of the twin towers demolition