French police announced last night that as many as 40 trucks and cars may have been engulfed by the fire, making it probably the worst road tunnel accident in history.
Serious questions about the safety of the tunnel were raised by rescue organisations last year. They warned in a report that the ventilation system would be hopelessly inadequate if a serious accident happened far from a tunnel mouth. This is exactly what happened almost at the mid- point of the tunnel - underneath western Europe's highest mountain, three and a half miles from the open air - on Wednesday morning. A Belgian lorry carrying margarine and flour skidded into the tunnel side. Seven other trucks piled up behind.
All the vehicles destroyed appear to have been trapped in the inferno that followed, estimated by officials to have reached a temperature of 1,000 degrees Celsius. Italian firefighters finally reached the epicentre of the blaze yesterday, 48 hours later. Such was the ferocity of the fire that the rescue workers said it was difficult to tell how many victims had perished in the wreckage. "Inside the vehicles, you can see skeletons and human remains but... it is impossible to say how many," an Italian official said.
Some vehicles were still burning yesterday morning; others had been buried by rubble from the collapsed lining of the tunnel.
Eight drivers, including the driver of the Belgian truck thought to have caused the accident, are known to have escaped before the fire reached its height.
Other motorists were overcome by fumes as they tried to run to safety. Their bodies were found several hundred metres from the site of the crash, just beyond the halfway point between the French and Italian tunnel mouths. Other victims were found in "sealed" safety refuges, built eight years ago. The safe havens were designed to protect motorists from a fire for only two hours.
The director of the tunnel company, Remi Chardon, said earlier that at least 17 and up to 30 people were feared to have died. Eleven bodies had been accounted for by yesterday afternoon but now up to 30 more people are feared missing.
The judicial inquiry is expected to concentrate on the safety standards of the 34-year- old single-bore tunnel - especially the absence of an escape tunnel and the adequacy of the ventilation system.
The seven-mile-long bore, linking France and Italy, carries up to 4,000 trucks a day, many times the level of traffic for which it was designed in the early 1960s. Unlike long- distance road and rail tunnels built more recently, it has just one bore and two lanes, one each for northbound and southbound traffic. Safety precautions have been tightened in recent years.
Refuges equipped with telephones, and capable of sheltering up to 40 people were excavated every 600 metres in 1991. Closed-circuit television cameras were installed every few metres in 1995.
Both French and Italian firefighters criticised the ventilation system, unchanged since the tunnel was built and attacked in an official report last year. The system proved utterly incapable of pumping in cold air or removing the thick fumes from the burning margarine and flour and the loads of the other blazing trucks, including, it is believed, a tanker containing chlorine.
The narrow tunnel turned into a furnace. The heat was so intense and the fumes so thick that the first group of Italian firefighters who tried to approach the inferno were forced to retreat through the ventilation shafts. A group of French firefighters took refuge in one of the new safety zones but one of them died of a heart attack.