With little warning, the collapse occurred along a roughly 30-m-long section concourse built on an elevated platform in front of the $900-million Terminal 2E main building. Clad in glass, the 650-m-long concourse building is enclosed by a concrete vault, springing from a raised slab, with numerous square window openings.

With a flattened ellipse section, the vault spans around 34 meters and was erected in large precast ring sections by Paris-based GTM Construction. A joint venture led by Eiffel Construction Metallique SA, Metz. did detailed design and installation of the nonstructural steelwork envelope holding the glass enclosure.

To help investigations, project architect Paul Andreu was due back in Paris this Tuesday from China, where he is working on a major theater complex in Beijing. Andre led a team from the airport owner and operator Aéroport de Paris, which also undertook the structural design.

While the terminal 2E was closed to traffic, the similar, six-year-old Terminal 2F remains in operations. Though the buildings have similar designs, 2E has a timber ceiling while 2F is lined with heavy, nonstructural concrete. The concourse building also resembles the older terminal, but its exposed interior concrete is structural, explains an ADP architect.