Published: March 30, 2003

Matthys Levy, co-author of a controversial study on why the World Trade Center collapsed in the aftermath of the Sept. 11 terrorist attack, will present his findings as part of a public regional symposium sponsored by the National Academy of Engineering on April 10 at CU-Boulder.

The symposium, "Tall Buildings: Are They Safe Enough?" will be held from 2 p.m. to 5:30 p.m. in the new Discovery Learning Center at CU-Boulder's College of Engineering and Applied Science. The Discovery Learning Center is located on the southwest corner of Colorado Avenue and Regent Drive.

Levy, a principal in the civil engineering consulting firm Weidlinger Associates, is scheduled to present "Anatomy of a Disaster: The World Trade Center Investigation" at 4 p.m. His half-hour talk will include a presentation of the computer simulation Weidlinger Associates developed to depict the sequence of failures leading to the collapse of both towers.

The firm's analysis found no structural flaw in the building's design but concluded that fire weakened the vertical steel support columns so that they were unable to hold the weight of the floors above. Weidlinger's findings contradict the results of the initial federal investigation performed by the Federal Emergency Management Administration, which concluded that unconventional floor supports failed, leading to a progressive collapse of the buildings.

Other featured speakers at the symposium will be Shankar Nair, a leading structural engineer who has designed some of America's most innovative structures; Dennis Mileti, director of the Natural Hazards Center at CU-Boulder; and Bruce Ellingwood, distinguished professor of civil and environmental engineering at the Georgia Institute of Technology.

The order of presentations will be:

ÿ 2 p.m. - Opening Remarks by Bill Wulf, president, National Academy of Engineering; and Ross Corotis, CU professor and symposium organizer.

ÿ 2:20 p.m. - "Disasters by Design" presented by Dennis Mileti, director of the Natural Hazards Center at CU-Boulder. Mileti will pose the question whether engineers inadvertently increase our susceptibility to major disasters by designing and building skyscrapers that increase people's risk.

ÿ 3 p.m. - "Tall Buildings - Evolution Toward Vulnerability?" presented by Shankar Nair, senior vice president, Teng & Associates. Nair's work includes the structural design of numerous tall buildings of 30-70 stories and many major bridges, including long spans over the Mississippi River. He will discuss the evolution of the skyscraper and how he believes structural engineers should address the threat of terrorism in structural design.

ÿ 4 p.m. - "Anatomy of a Disaster: The World Trade Center Investigation" presented by Matthys Levy, principal, Weidlinger Associates.

ÿ 4:45 p.m. - "Probability-Based Structural Design: Acceptable Risk Bases" presented by Bruce Ellingwood, College of Engineering distinguished professor, Georgia Institute of Technology. Ellingwood will discuss the role of probability in design.

"The goal of the symposium is to provide information to the public on how the engineering profession assesses and responds to the hazards faced by society. Since Sept. 11, that has included the threat of terrorism to buildings and skyscrapers throughout the United States," said Ross Corotis, CU-Boulder professor of civil engineering and symposium organizer.

A reception will be held in the lobby of the Discovery Learning Center following the symposium. For more information, contact Carol Rowe in the College of Engineering and Applied Science at (303) 492-7426.