World Trade Center Building Performance Study
   (official site, all PDF files)
   May 2002
   http://www.fema.gov/rebuild/mat/wtcstudy.shtm

The FEMA WTC Building Performance Study
   (same text in web-readable HTML, with commentary)
   May 2002
   http://911research.wtc7.net/wtc/official/fema.html

Official Pentagon Investigations  (FEMA, Purdue)
   January 2003
   http://911research.wtc7.net/pentagon/official/index.html

EPA's Response to the World Trade Center Collapse:
Challenges, Successes, and Areas for Improvement
   August, 2003
   http://www.thememoryhole.org/911/epa-response/epa-911-response.html
   Note: This is the Inspector General's analysis of EPA's response,
   not EPA's original statements.

Congress: Joint Inquiry into Intelligence Community Activities
before and after the Terrorist Attacks of September 11, 2001
   December 2003
   http://www.gpoaccess.gov/serialset/creports/911.html   or
   http://www.thememoryhole.org/911/joint-report/

Report of The National Commission on Terrorist Attacks
Upon the United States  (The 9-11 Commission)
   August 2004
   http://govinfo.library.unt.edu/911/report/

9/11 Commission Staff Monographs and Statements
   August 2004
   http://www.9-11commission.gov/staff_statements/

NIST: Reports of the Federal Building and Fire Investigation
of the World Trade Center Disaster
http://www.nist.gov/el/disasterstudies/wtc/

• Twin Towers (August & December 2007)
  http://www.nist.gov/manuscript-publication-search.cfm?pub_id=909017
     Draft (September 2005, local)
• Building 7 (August & November 2008)
  http://www.nist.gov/manuscript-publication-search.cfm?pub_id=861610