I worked for the builders. We maintained the Port Authority's police, maintenance, and operations radio, public address, and CCTV systems. The control point for our police radio primary systems were on the top floor of one of the towers. Our radiax antenna systems ran through the buildings. Our external antennas were on the roof.
My degree is in the physical sciences, not engineering but I understand simple applied physics. The conspiracy theories regarding the 2001 attacks are sheer fantasy and delusional at best, an insane affront to the thousands that died on site or later from the consequences at worst.
I was bothered by the poor response of our air national guard to the incident. At one time an ANG wing responded rapidly to any incursions to our air space by unidentified aircraft, but that was during the cold war era. These commercial flights were identified and nothing amiss was even suspected until the flights deviated from ATC instructions. No one on the ground even considered an attack in progress until the second tower was struck.
The engineering analysis that we were privileged to view as part of the engineering department wasn't a public release. An agency whose managers ' greatest concern was public perception of the agency, wasn't about to tell the general public that the buildings were designed to implode and collapse. That would amount to taking direct responsibility for all the lives lost in the collapse, despite the fact that it minimized collateral damage.
The first attack in 1993 destroyed a large portion of the garage substructure including the WTC police desk. This was a car bomb parked in the garage and while a few dozen people were killed, including some of the WTC police, the building didn't collapse, which was the intent of the bombers.
After that attack new security protocols were instituted including vehicle inspections upon entry. Multiple security camera systems were installed. A floor was devoted to facility wide surveillance extending to other Port facilities. A "suspicious activity awareness" and reporting system was instituted (and observed by long time employees like me who had no desire to be blown up,) Many restricted zones were setup in all of our facilities to limit access even to photographic reconnaissance of critical infrastructure.
In 2001 security for the trade center was very tight, meeting national standards, and employees felt secure from any ground attacks.
The federal investigation into the terrorist planning revealed that the attackers had entered the country more than a year in advance in order to adjust to the nuances of our law enforcement and security protocols, as well as to train in flight schools on how to steer the aircraft.
The mastermind of the latter attacks, Osama Bin Laden, was a Saudi National (a national ally ) and had been trained in methods of insurgency and terrorism by our own CIA during the Soviet occupation of Afghanistan. He was an educated and intelligent man to begin with and trained by our best "black ops." personnel.
There might have been some massive stupidity on the part of our intelligence community in training potential enemies, but that community was aware that attacks were being planned and executed. Unfortunately their intelligence wasn't sufficient to prevent the attacks. However, the increased surveillance of the general public under the patriot act definitely did prevent a number of attacks that were planned after 2001, but at the expense of privacy and contrary to a number of laws protecting civil liberties.
