Oklahoma City bombing

===Building security and construction===
[[File:DemolishedAMbuilding.jpg|thumb|right|300px|alt=Two images are stitched together showing the site of where the building stood prior to its demolition. A crowd of people are visible in front of the chain link fence blocking entrance to the site. Large piles of dirt can be seen on the site as well as damage to nearby buildings.|The site of the building after it was demolished, three months after the bombing]]
In the weeks following the bombing, the federal government ordered that all federal buildings in all major cities be surrounded with prefabricated [[Jersey barrier]]s to prevent similar attacks.<ref name="Salon">{{cite news|last=Manjoo |first=Farhad |title=Cityscape of fear |work=[[Salon (website)|Salon]] |url=http://www.salon.com/news/feature/2006/08/22/architecture/ |date=August 26, 2006 |archive-url=https://web.archive.org/web/20110218065059/http://www.salon.com/news/feature/2006/08/22/architecture |archive-date=February 18, 2011 |url-status=dead}}</ref> As part of a longer-term plan for [[United States federal building security]], most of those temporary barriers have since been replaced with permanent and more aesthetically considerate security barriers, which are driven deep into the ground for sturdiness.<ref name="InvisibleInsurrection">{{cite news|last=Hill |first=John |title=Changing Place/Changing Times |work=Invisible Insurrection |year=2004 |url=http://www.archidose.org/writings/insurrection.html |archive-url=https://web.archive.org/web/20110112232644/http://www.archidose.org/writings/insurrection.html |archive-date=January 12, 2011 |url-status=dead}}</ref><ref name="CIO">{{cite news|last=Duffy |first=Daintry |title=Hidden Strengths |date=December 9, 2003 |work=CIO Magazine |url=http://www.cio.com.au/index.php/id;759321961 |archive-url=https://web.archive.org/web/20110807172418/http://www.cio.com.au/article/182068/hidden_strengths |archive-date=August 7, 2011 |url-status=dead}}</ref> All new federal buildings must now be constructed with truck-resistant barriers and with deep setbacks from surrounding streets to minimize their vulnerability to truck bombs.<ref name="SMC">{{cite web|title=Safeguarding Building Perimeters For Bomb Attacks |publisher=Security Management Consulting |url=http://www.secmgmt.com/safeguarding-building-perimeters-for-bomb-attacks/ |archive-url=https://web.archive.org/web/20110716030021/http://www.secmgmt.com/safeguarding-building-perimeters-for-bomb-attacks/ |archive-date=July 16, 2011 |url-status=dead}}</ref><ref name="PoP">{{cite journal|last=Dixon|first=David|title=Is Density Dangerous? The Architects' Obligations After the Towers Fell|journal=Perspectives on Preparedness|date=October 2002|url=http://belfercenter.ksg.harvard.edu/files/is%20density%20dangerous.pdf|access-date=June 5, 2009|archive-url=https://web.archive.org/web/20131224113813/http://belfercenter.ksg.harvard.edu/files/is%20density%20dangerous.pdf|archive-date=December 24, 2013|url-status=live}}</ref><ref name="McHC">{{cite news|last=Nadel |first=Barbara A. |title=High-risk Buildings Placed in a Class All Their Own |date=March 25, 2002 |work=[[Engineering News-Record]] |url=http://enr.construction.com/features/buildings/archives/020325c.asp |archive-url=https://web.archive.org/web/20110416232540/http://enr.construction.com/features/Buildings/archives/020325c.asp |archive-date=April 16, 2011 |url-status=dead}}</ref> FBI buildings, for instance, must be set back {{convert|100|ft|m}} from traffic.<ref name="WPFairfaxAgents">{{cite news|last=Markon|first=Jerry |title=FBI's Fairfax Agents Packing For Pr. William |date=October 25, 2006 |newspaper=[[The Washington Post]] |url=https://www.washingtonpost.com/wp-dyn/content/article/2006/10/24/AR2006102401239_pf.html |archive-url=https://web.archive.org/web/20121110120452/http://www.washingtonpost.com/wp-dyn/content/article/2006/10/24/AR2006102401239_pf.html |archive-date=November 10, 2012 |url-status=dead }}</ref> The total cost of improving security in federal buildings across the country in response to the bombing reached over $600&nbsp;million.<ref name="Unfinished29">{{cite book|last=Linenthal|first=Edward|title=The Unfinished Bombing: Oklahoma City in American Memory|page=29|isbn=978-0-19-516107-6|year=2003|publisher=Oxford University Press }}</ref>

The Murrah Federal Building had been considered so safe that it only employed one security guard.<ref name="Apocalypse41">{{cite book|title=Apocalypse in Oklahoma|last=Hamm|first=Mark S|page=41|isbn=978-1-55553-300-7|year=1997|publisher=Northeastern University Press }}</ref> In June 1995, the DOJ issued ''Vulnerability Assessment of Federal Facilities'', also known as ''The Marshals Report'', the findings of which resulted in a thorough evaluation of security at all federal buildings and a system for classifying risks at over 1,300&nbsp;federal facilities owned or leased by the federal government. Federal sites were divided into five security levels ranging from Level 1 (minimum security needs) to Level 5 (maximum).<ref name="WBDGAssets">{{cite news|author=WBDG Safe Committee |title=Security for Building Occupants and Assets |date=October 31, 2008 |publisher=Whole Building Design Guide |url=http://www.wbdg.org/design/provide_security.php |archive-url=https://web.archive.org/web/20110315081503/http://www.wbdg.org/design/provide_security.php |archive-date=March 15, 2011 |url-status=dead}}</ref> The Alfred P. Murrah Building was deemed a Level 4 building.<ref name="JusticeRecommendations">{{cite news|author=WBDG Safe Committee |title=Justice Department Issues Recommendations For Upgrading Federal Building Security |date=June 28, 1995 |publisher=[[United States Department of Justice]] |url=https://www.justice.gov/opa/pr/Pre_96/June95/365.txt.html |archive-url=https://web.archive.org/web/20111027161311/http://www.justice.gov/opa/pr/Pre_96/June95/365.txt.html |archive-date=October 27, 2011 |url-status=dead}}</ref> Among the 52&nbsp;security improvements were physical barriers, closed-circuit television monitoring, site planning and access, hardening of building exteriors to increase blast resistance, glazing systems to reduce flying glass shards and fatalities, and structural engineering design to prevent [[progressive collapse]].<ref name="SecurityCivicsLessons">{{cite web |last=Nadel |first=Barbara A. |title=Oklahoma City: Security Civics Lessons|volume=2|issue=4|date=April 2007 |website=Buildings.com |url=http://www.buildings.com/newsletters/detail.aspx?contentID=4975 |access-date=June 5, 2009 |archive-url=https://web.archive.org/web/20071215033058/http://www.buildings.com/newsletters/detail.aspx?contentID=4975 |archive-date=December 15, 2007}}</ref><ref name="DesigningSecurity">{{cite news|last=Nadel|first=Barbara A.|title=Designing for Security|work=[[Archit. Rec.|Architectural Record]]|url=http://archrecord.construction.com/resources/conteduc/archives/research/3_98_1.asp|access-date=June 4, 2009|archive-url=https://web.archive.org/web/20121006164304/http://archrecord.construction.com/resources/conteduc/archives/research/3_98_1.asp|archive-date=October 6, 2012|url-status=live}}</ref>

The attack led to engineering improvements allowing buildings to better withstand tremendous forces, improvements which were incorporated into the design of Oklahoma City's new federal building. The [[National Geographic Channel]] documentary series ''[[Seconds From Disaster]]'' suggested that the Murrah Federal Building would probably have survived the blast had it been built according to California's earthquake design codes.<ref name="SecondsDisaster">{{cite episode|title=The Bomb in Oklahoma City (Oklahoma City)|series=[[Seconds From Disaster]]|season=1|number=episode 3|network=[[National Geographic Channel]]|airdate=July 20, 2004}}</ref>