A technical inquiry will be launched on Monday into the collapse of part of a terminal at Paris' Charles de Gaulle-Roissy airport, now known to have killed four people.
The cause of the collapse is not known
A section of roofing crashed onto a departure lounge, sending the entire section of the building plunging onto service vehicles below.
Rescuers revised the death toll down from five after confusion over remains found at the scene.
Prime Minister Jean-Pierre Raffarin promised a full investigation.
"The authorities have been mobilised," he said at the scene of the tragedy on Monday morning.
"Obviously we are thinking of the families of the victims and we are very attentive to any inquiry which allows us to find out the truth about this accident."
The head of the rescue team, Colonel Frederic Monard, said specialists with sniffer dogs would make a final round of the site on Monday to check that nothing had been missed.
"We hope we won't have to find any more victims," he told AFP news agency.
He explained that on Sunday the dogs had identified human remains in five different locations, hence the initial reports that five people had died.
Three other people were slightly injured.
The Chinese government said two of the dead were Chinese travellers.
AFP said a Czech woman was also identified among the dead, but the nationality of the other victim is still not known.
The building had been opened for less than a year, but the project's architect said he would not speculate on possible causes.
Paul Andreu, who is currently working on a new National Theatre in the Chinese capital, Beijing, said he would fly back to France at once.
"On my return, I will place myself at the disposal of the French airport authorities," he said on Sunday.
He added that the concrete, glass and metal structure was "nothing revolutionary".
The accident happened early on Sunday morning, when there were few passengers in the building.
CHARLES DE GAULLE AIRPORT
Named after the French statesman
Also known as Roissy Airport
Began service in March 1974
France's main airport and one of Europe's largest
Has three terminals
Connected to commuter rail network and high speed TGV rail lines
25 July 2000 Air France Concorde crashed after coming into contact with runway debris
Emergency information on rescue and flights
+33 1 48 64 59 59
The victims were crushed beneath slabs of concrete, metal and glass which fell from the roof of the departure lounge in terminal 2E.
It was 0700 (0500 GMT) and flights from New York and Johannesburg had just arrived at the terminal. A flight to Prague was due to depart.
An investigation is likely to focus on whether there was a fault in the design of the ultra-modern building, or whether short cuts had been taken when it was built.
Investigators have raised the possibility of bringing charges of involuntary manslaughter.
Terrorism has been ruled out as a possible cause.
Terminal 2E cost 750m euros (£500m) to build and was opened in June 2003 after delays caused by security concerns and trade union accusations that construction was being rushed.
The building is used by Air France and the Sky Team alliance.
Paris correspondent Hugh Schofield says the terminal was a key part of the strategy to turn Paris into Europe's leading airport hub.
That vision has now been dealt a grievous blow, he says.