as a result of the call-in program, that contention was challenged by the Sept. 11 commission, which found little evidence to support that claim. In 2011, DHS suspended the program on efficiency grounds, stating that all NSEERS information was now collected from other sources. It completely glossed over the program's civil liberties costs and did not communicate with those harmed by the program, according to the ACLU. NSEERS was finally officially terminated in 2016 by the Obama administration in order to make it more difficult for president-elect Donald Trump to achieve his goal of introducing a Muslim registry. Investigations Collapse of the World Trade Center A federal technical building and fire safety investigation of the collapses of the Twin Towers was conducted by the United States Department of Commerce's National Institute of Standards and Technology (NIST). The goals of this investigation, completed on April 6, 2005, were to investigate the building construction, the materials used, and the technical conditions that contributed to the outcome of the WTC disaster. The investigation was to serve as the basis for: Improvements in the way in which buildings are designed, constructed, maintained, and used Improved tools and guidance for industry and safety officials Revisions to building and fire codes, standards, and practices Improved public safety The report concludes that the fireproofing on the Twin Towers' steel infrastructures was blown off by the initial impact of the planes and that, if this had not occurred, the towers would likely have remained standing. The fires weakened the trusses supporting the floors, making the floors sag. The sagging floors pulled on the exterior steel columns to the point where exterior columns bowed inward. With the damage to the core columns, the buckling exterior columns could no longer support the buildings, causing them to collapse. In addition, the report asserts that the towers' stairwells were not adequately reinforced to provide emergency escape for people above the impact zones. NIST stated that the final report on the collapse of 7 WTC will appear in a separate report. Internal review of the CIA The Inspector General of the CIA conducted an internal review of the CIA's performance prior to 9/11, and was harshly critical of senior CIA officials for not doing everything possible to confront terrorism, including failing to stop two of the 9/11 hijackers, Nawaf al-Hazmi and Khalid al-Mihdhar, as they entered the United States and failing to share