PARIS, May 24: A futuristic new terminal at Paris' Charles de Gaulle airport may have to be demolished after a walkway roof collapsed, killing at least five people , the head of the city's airports authority said as investigators struggled on Monday to determine the cause of the disaster.

"If all the parts that make up this terminal are beyond repair, we will demolish all of it, of course. We will not take any risk in matters of safety," Pierre Graff told the newspaper Le Parisien.

Several tonnes of concrete, metal bars and glass panelling came crashing down on an arrival and departure passageway at the main Paris airport's showcase Terminal 2E early on Sunday, strewing rubble over a 30-meter area.

A section of the glass-encased walkway also caved in, falling onto service vehicles parked below. Officials said at least five people were killed and three injured. Rescuers worked throughout night to clear the rubble from the site.

The new terminal was inaugurated only last June, amid delays caused by security concerns and trade union accusations that management was rushing the completion deadlines for the building.

French President Jacques Chirac expressed his "deepest sympathies" for the families of the victims and was joined by Prime Minister Jean-Pierre Raffarin in calling for an immediate investigation.

Prosecutors launched an inquiry to find out who or what was responsible for the casualties. Transport Minister Gilles de Robien earlier ruled out the possibility of an attack. But Graff told Le Parisien the cause of the accident was unclear.

"Since yesterday (Sunday), architects and engineers are at work... They are like us. They are stunned, they don't understand," the head of the Paris airports authority (ADP) said.

"We are going to close the whole terminal as a precaution... ADP is ready to assume its responsibilities... If the families of the victims are to be compensated, we will do it."

The investigation was likely to concentrate on faults in the terminal design or possible short-cuts taken in the construction. The walkway roof collapsed as Air France flights from Newark and Johannesburg had just arrived and another to Prague was just about to depart.

Had it occurred at a peak travel time and not on a Sunday morning, the toll could have been higher. Police officers were direct witnesses to the disaster as it struck. They were on the scene, having spotted dust coming from a crack in the roof about 25 minutes before it collapsed and were trying to cordon off the area.

The terminal was immediately evacuated and some 200 fire fighters backed by police and army officers were rushed to the site. Rescue teams with sniffer dogs were called in to search the rubble for survivors.

Meanwhile, the French architect who designed the terminal, Paul Andreu, said on Monday he would immediately return to France from Beijing. "I'm cutting short my stay here. I am shocked and will return tomorrow (Tuesday) to Paris," he told AFP in the Chinese capital, where he is working on the city's new landmark National Theatre.

"I don't for a minute want to speculate on what might be the cause of the accident. On my return, I will place myself at the disposal of the French airport authorities."

He said the design of the terminal might have been "bold", but the materials used were "nothing revolutionary". At least one of the dead was Chinese, a man identified by Xinhua news agency as Wu Xin, a member of a Chinese trade delegation.

A woman member of the delegation was "missing", Xinhua added. A Czech woman was also identified among the dead although the nationalities of the other victims were not immediately known.

The opening of the terminal, the latest addition to the burgeoning Paris hub, was delayed for a week last June after fire officials and engineers ruled that safety norms had not been met - an overhead light had lost its fittings and crashed down during an inspection tour.

Management at ADP subsequently blamed the delay on the workforce - prompting an angry reaction from the CGT union, which accused Air France management and ADP of setting an unrealistic deadline for the opening. -AFP