CONCRETE ARCHES beneath the Mont Blanc tunnel road deck have been weakened by the heat of the blaze and are now feared to be unstable, according to investigating magistrate Bruno Charve.
Speaking on Monday, Charve said this meant salvage teams were concerned that the road would collapse under the weight of the three-axle salvage truck being used to remove vehicles from the tunnel.
Temperatures inside the tunnel took until Saturday to fall to around 30degreesC, low enough to allow salvage teams and investigators to start work.
The first vehicles to be salvaged from the tunnel emerged from the French side on Sunday afternoon. Head of the rescue operation, Phillipe Gaultier, said that chunks of concrete falling from the shattered tunnel roof had hampered efforts to recover vehicles and bodies. Work had to be stopped on Monday after a large section of the tunnel roof collapsed.
It is expected that the tunnel will remain closed for some months while investigations and repairs are carried out.