Live lab - strength of materials and reason for symmetric collapse of New York Trade Center in 2001

The attack on and subsequent collapse of the New York Trade Center ("Twin Towers") in 2001 has attracted many conspiracy theories. But the fact is that this type of collapse is exactly what Materials scientists and engineers would expect under such high temperature conditions.
In this experiment we show that a steel bar under load, when subjected to a high temperature (as happened in the NYWTC), it will first expand, breaking all connections with the other bars it is connected to, and then collapse because of loss of load-bearing capacity, i.e. compressive strength. Since such expansion occurs in all directions and loss of strength is catastrophic even at temperatures as low as 700 degrees Celsius, the collapse will be symmetric. As soon as the top floors collapsed, they crashed onto the floors below which were supported by already weakened vertical bars and this led to the domino effect seen in 2001.

[bradmomohara]

Impact resistance is elementary school basic. The way you ignore it with such skill makes me think NIST was waving money behind the camera as propaganda incentive.