The U.S. President’s Commission on Critical Infrastructure Protection (PCCIP), convened in the wake of the bombing of the Murrah Federal Building in Oklahoma City, concluded that the nation’s physical security and economic security depend on our critical energy, communications, and computer infrastructures. While a primary motivating event for the establishment of the commission was the catastrophic physical attack of the Murrah Building, it is ironic that the commission focused its attention primarily on cyber threats. Their rationale was that cyber vulnerabilities posed a new, unaddressed challenge to infrastructure security. This approach was further questioned by the events of September 11, 2001 and the subsequent bio-threat events in America.

During and shortly after the convention of the President’s Commission on Critical Infrastructure Protection in 1997-99, a working group met to look into the physical protection of critical U.S. infrastructure using underground structures. This “Underground Structures Infrastructure Applications” (USIA) group provided a timely balancing discussion of issues surrounding the physical vulnerability aspect of the infrastructure protection problem. The group convened a workshop on the subject under the auspices of the National Research Council’s Board on Infrastructure and the Constructed Environment. The present paper draws on the working group deliberations and NRC Workshop proceedings to address infrastructure assurance in the context of maximizing the physical protection of high value infrastructure by the use of underground construction. Although the PCCIP did not directly address a role for underground facilities (UGFs), its final report recommended a program of government and industry cooperation and information sharing to improve the physical security of critical United States infrastructure.

We develop specific recommendations for the use of underground facilities to support implementation of the general PCCIP challenge. It is our contention that underground facilities reduce the risk of infrastructure disruption from both physical and cyber attacks. In the latter case, undergrounds provide secure reserve operations and back-up data storage locations to ensure the reconstitution of critical electronic information systems. In addition, noting that the Norwegians have placed much of their critical infrastructure underground, we provide information on the Norway’s experience gathered on a fact-finding trip to that country organized by one of the authors. The events of September 11th, 2001 and the use of underground locations for terrorist security by the Taliban, provide a strong impetus for the use of underground construction to protect vital infrastructure.