A 120-foot section of the new concrete-and-glass tube terminal at Paris’ Charles de Gaulle airport collapsed May 23, less than a year after it opened at a cost of about $900 million.

A 120-foot section of the new concrete-and-glass tube terminal at Paris’ Charles de Gaulle airport collapsed May 23, less than a year after it opened at a cost of about $900 million. The collapse killed four people and injured several others.

The project’s requirements specified that the 2,100 foot-long, 110-foot wide terminal not have any intermediate interior supports that would restrict passenger flow. The terminal was designed by Paul Andreu, who used principles of tunnel building to design the facility that services primarily Air France.The concrete shell relied on interlocking rings with steel hoops outside and carbon fiber reinforcements glued on the shell. Several experts said that Andreu’s design, while unusual, was probably not to blame.

Mistakes are more likely when different companies are responsible for different parts of the building, several engineers said. GTM Construction was responsible for the concrete shell and Hervé, for the columns. The terminal was expected to handle 10 million passengers by the end of 2004.