21st Century Security and CPTED, 2nd Edition

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17

Protecting Buildings and

Infrastructure with CPTED

The attacks on the World Trade Center and the Pentagon and the Oklahoma City bombing are

forever etched as terrorism landmarks in our collective memory. Terrorism represents a real threat

for our society and to our peace of mind. The face of terrorism is undergoing systemic changes as

the level of terrorist sophistication increases with the availability of knowledge and materials with

which to carry out these acts of violence. Knowledge about bombs and terror has proliferated to the

point that virtually any terrorist or criminal can nd the information needed to build virtually any

kind of explosive device.

Timothy McVeigh, who blew up the Alfred R. Murrah Federal Building, stated in an interview

shortly after his arrest that he picked that particular building because “it was more architecturally

vulnerable.” Who would have ever thought that a rental truck and a load of manure could be so

deadly (see Figure 17.1)?

What can we do to diminish the threats and losses to persons, information, and property? How

do you reduce the opportunity and fear of terrorism in the built environment with Crime Prevention

Through Environmental Design (CPTED)? This chapter will address how to reduce the threats and

vulnerabilities in buildings by changing how we design and use our spaces.

LESSONS LEARNED FROM THE WORLD TRADE CENTER

People watching the horror on live TV were shocked that the World Trade Center buildings col-

lapsed. The towers, built in 1972–1973, were 110 stories tall, and experienced progressive structural

collapses similar to that caused by the 1995 explosion to the Alfred R. Murrah Federal Building in

Oklahoma. The two plane crashes into the towers destroyed columns and oors on several stories,

which transferred excessive loads to the remaining structural columns. Explosions and raging

re weakened the remaining columns, which were already overloaded. The original design had

provided for the structural strength to withstand a Boeing 707, which was a large jet of its time

but held a lower fuel capacity. The design of the towers was substantial enough to withstand the

impact of a jet without toppling instantly. Even with huge gaping holes, the remaining columns were

sufciently strong to hold the structure up for over 45 min and allow 20,000 people to escape. The

jet fuel released a much higher heat than paper or plastic burning, which might be the contents of a

normal ofce re. Fire suppression systems in the towers did not include foam sprinklers that could

deal with the jet fuel res. Both of the crashed jets were fully fueled for transcontinental ights,

making them ying bombs.

CONTENTS

Lessons Learned from the World Trade Center ............................................................................. 275

GSA Standards: Architectural Guidelines for Federal Facilities ................................................... 276

What about Buildings in the Private Sector? .................................................................................279

Application of ISC Standards to All Building Types ..................................................................... 286

Summary ........................................................................................................................................ 286

References ......................................................................................................................................287