By Hugh Schofield
Judicial, technical and internal inquiries into the disaster at Charles de Gaulle airport's Terminal 2E are getting under way - and already it's possible to imagine the main avenues of inquiry.
The airside departure lounge was the scene of the collapse
Transport Minister Gilles de Robien has ruled out terrorism, so the principal suspects will be either a design fault in the architecture of the ultra-modern building or oversights in its construction.
Either explanation will be a massive embarrassment for the airport's manager, Aeroports de Paris (ADP), as well as for Air France and indeed the French government itself.
Terminal 2E was supposed to be the latest in airport design.
Designed by Paul Andreu at a cost of 750 million euros, it consists of two long, sleekly curving halls linked by a central passageway or "isthmus."
It was part of the outer of the two halls, the "jetty" that serves as flight-side departure lounge, that inexplicably collapsed on Sunday morning.
Planned capacity was for 10m passengers, with the latest in check-in procedures, flat screen information terminals and space for the future giant Airbus 380s.
The terminal, as well as its sister 2F, was a key part of the strategy to turn Paris into the leading European airport hub.
It is that vision that has now been dealt a grievous blow.
For the want of any other trail to follow, news media in France were on Sunday recalling the inauspicious events that surrounded the terminal's opening last June.
Due to be inaugurated on 17 June, there was a delay of a week after a committee of engineers and safety officers found that security was not up to standard.
Six people were killed by the collapsing roof
It was reported that a large lamp actually fell to the ground during their inspection.
One union, the hardline CGT, said that completion of the terminal had been rushed, overriding objections made by the workforce.
"Everyone knew from the progress of the work that [the 17 June deadline] was unreasonable," it said.
The implication raised by the union was that for purely commercial reasons, that is the need to open Terminal 2E as soon as possible, corners had been cut.
As well as examining the building standards, investigators will also want to check out the possibility of some inherent flaw in the conception of the building.
Pride before a fall
France has been through a long list of disasters linked to major projects.
One thinks of the collapse of a passageway onto the super-liner Queen Mary II, the fire in the Mont Blanc tunnel, the explosion at the AZF factory in Toulouse.
Built in four years between 1999 and 2003
Cost: 750m euros (£500)
Floor space: 104,000 sq m
Capacity: six million passengers a year
Made from reinforced concrete and 36,000 sq m of glass
Plane parking gates: 10
Then there are the much-reported flaws in the architectural "grands projets" launched by President Francois Mitterrand in Paris.
The bits that fell off the La Defense arch; the unusable stage machinery at the Opera; the fading books in the Bibliotheque Nationale.
Do these have anything in common?
Not really, only the inherent risk that attaches to any enterprise of scale and ambition.