NIST video wtc tower collapse access explosives demolition

NIST Video - Malfunctioning Elevator in WTC Tower

More NIST video stuff for you. Admittedly, this goes directly into the "highly speculative" category. Often, people will ask how could people have access to the towers and their infrastructure in order to place the explosives that would be needed for an explosive demolition? Yes, I know about the Securacom Security and Marvin Bush connection, but that doesn't address the practical, logistical manner in which something like this could occur.