59 minute, 49 second, KPFA show on mp3:
Guns and Butter - "Demolition Access To the World Trade Center Towers" with Kevin Ryan.
https://archives.kpfa.org/data/20110112-Wed1300.mp3
"WTC tenants, both companies and employees; security and design firms and their board members involved in redesigning and implementing the new security system after the 1993 basement bombing; companies and individuals involved in the clean-up of ground zero. Who had the means, access, motivation and who profited."
An interesting set of questions are brought up in this interview that should have been more thoroughly investigated by FBI, NISTand the 911 Commission.