Mont Blanc Tunnel: When a burning truck killed 39 people

It is around 10.45 a.m. on a Wednesday morning when 57-year-old Belgian Gilbert Degraves drives his 40-ton truck through the tollbooth on the French side of the Mont Blanc tunnel. The truck is loaded with margarine and flour destined for a food factory in Milan.

The 11.6 km long Mont Blanc Tunnel is the deepest tunnel in the world and lies 2478 meters below the summit of Europe’s highest mountain at 4810 meters. When the first cars rolled through here on July 19, 1965 after four years of construction, the French and Italians had completed a project of the century. It was this tunnel that enabled year-round road traffic across the Alps between Chamonix on the French side and Aosta on the Italian side. The tunnel has 18 fire protection rooms – one every 600 meters – and 77 emergency telephones.

Tunnel sensors were disabled due to false alarms

After about two kilometers in the tunnel, white smoke rises behind the driver’s cab of Degrave’s truck, but he only notices it when he is already in the middle of the tunnel. The professional driver turns on the hazard warning lights. At around 10:52 a.m., the smoke is so thick that it triggers the tunnel sensors, which react to poor visibility in the tunnel. The driver finally stops the truck and gets out. A traffic jam quickly forms. Then suddenly the driver’s cab is on fire and burns brightly. The driver escapes from the tunnel shaft in the direction of the Italian side.

At 10:54 a call from an emergency telephone reached the Italian control room. The sensors had only triggered the alarm on the French side, on the Italian side it was switched off the day before due to a false alarm. Finally, the tunnel is closed to other vehicles and the rescue workers are on their way.

As the smoke thickens, the first cars that entered the tunnel from Italy turn around again. An employee in the control room, who is observing the scenario via cameras, is pumping fresh air at them. A fatal mistake: the murderous smoke shoots at 4.5 meters per second over the cars behind the burning truck. Soon the entire French side of the tunnel is filled with smoke.

Eyewitness: “There were six explosions, very close together”

The smoke blackened the video cameras of the surveillance system. The rescue workers do not know that many people are trapped in their cars behind the burning truck. Some of them panic and try to drive away. But because of the lack of oxygen, the engines fail. A few leave their vehicles to visit the fire shelters. Most, however, lose consciousness after a few minutes due to the dense, toxic smoke.

When the Italian rescuers came within a few meters of the truck, there was a sudden bang. “There were six explosions, very close together,” recalls an eyewitness in a TV documentary about the accident. “It just went bang, bang, bang, bang, bang, bang. Really fast. Those were really powerful explosions.”

It’s the tires that explode and shoot through the air like bullets. The firefighters withdraw, saving a few people from the vehicles on the way. The fire has since spread to other cars. In addition to the Belgian’s Volvo, another truck was loaded with margarine. Margarine has a very high energy content. When melted, it’s almost as dangerous as gasoline. And two more of the 14 trucks trapped in the tunnel also have loaded large amounts of polyethylene. They make the inferno rage even worse. Even experienced experts are surprised that a truck loaded with margarine and flour can burn as badly as a tanker loaded with 30,000 liters of gasoline.

Mont Blanc Tunnel fire burns for three days

The temperature in the tunnel is now more than a thousand degrees. A cruel heat, which even the shelters are not up to. Above the source of the fire, the steel reinforcement of the concrete ceiling melted over a length of around 100 meters, and heavy rocks crashed onto the vehicles. At some point it is no longer possible for the firefighters to get to the source of the fire.

The fire rages for three days. Little is left of the victims other than tooth fragments, ashes and wedding rings. The last victim can only be identified five months after the disaster. Fire protection technicians suspect a discarded cigarette butt, which may have ignited the air filter of the Volvo FH12, to be the cause.

In a subsequent process, a total of 16 suspects have to answer for negligent homicide. The then president of the French tunnel company ATMB, Rémy Chardon, was sentenced to two years’ probation and the tunnel companies were fined a total of 300,000 euros.

The driver of the truck also received a suspended sentence of four months. He tells the judges that he did everything he could do. Even in the process six years after the disaster, he didn’t know what he could do better in a similar situation. “I couldn’t do anything else,” said Degrave, in a 2002 interview with the star explained that he had the feeling that the judiciary was trying to make him a scapegoat. His boss at the time fled to Ecuador because of the matter. “It turned out that he let me work illegally. As a result, unions and associations withdrew from me. I am not entitled to any claims for support”. He denied responsibility for the disaster.

The accident completely paralyzed the Mont Blanc Tunnel for around three years and triggered a worldwide discussion about safety precautions. Today it is praised for its modern safety and ventilation systems. The fire protection rooms were redesigned and now offer direct access to the escape tunnel under the road. With the new ventilation system, the air can be directed in a targeted manner and in the event of a fire, the toxic smoke gases are automatically blown out of the tunnel. Today, only a memorial with a stone memorial near the tunnel entrance reminds of the catastrophe of that time.

Swell: National Geographicstern.de, atropedia.net