At least 10 people were killed after a head-on collision between two trucks led to a major fire in the 17 km-long Gotthard Tunnel in Switzerland.
Rescue workers were beaten back by intense heat and billowing clouds of noxious smoke from burning tyres, the cargo of one of the trucks.
"According to my information there are at least 10 dead," said Mr Karl Egli, a local police spokesman, adding that further deaths could not be ruled out.
Another police spokesman said that the intense heat had caused a 300-metre stretch of the roof to collapse around the accident scene in the tunnel.
"It's not just the two trucks involved, there were several other vehicles involved in the accident," said Mr Herbert Planzer, after rescue crews finally reached the accident scene yesterday afternoon.
The accident happened shortly after 10 a.m. yesterday when two trucks collided around 2 km from the southern entrance of the tunnel, the second-longest road tunnel in the world and Switzerland's most important north-south axis.
Eye-witnesses, who escaped through the adjacent emergency tunnel, spoke of intense heat, thick black smoke and the smell of burning rubber. Others said they heard explosions. At least six people evacuated from the tunnel were flown to hospital by helicopter.
The tunnel was opened in 1980, and, despite an average of five minor fires annually, its security was rated as "good" in a recent survey by ADAC, the German equivalent of the AA.
The design of the tunnel was criticised, however, with the narrow escape tunnels inaccessible to emergency vehicles, forcing them to use the main tunnel.
Tunnel fans extracted much of the smoke from the tunnel by late afternoon allowing emergency crews into the tunnel. However, with the southern entrance still inaccessible, over 150 rescue workers were forced to use the northern tunnel entrance and travel almost the full length of the tunnel to reach the accident scene.
Preliminary reports suggested one of the truck drivers survived the crash, and that a burst tyre on one of the trucks may have caused the accident.
The tunnel carries over 18,000 vehicles a day, 1.2 million vehicles annually, from the town of Goeschenen in the north to Airolo in the canton of Ticino, near the Italian border. The tunnel will remain closed for the forseeable future, authorities said yesterday.
Traffic will be diverted onto the winding St Gotthard Pass, which often remains closed for the winter months because of bad weather.
Traffic in the Gotthard Tunnel had increased steadily since the 1999 Mont Blanc Tunnel fire that left 41 dead. Mont Blanc, an 11-km road tunnel linking France and Italy, is scheduled to reopen next month.
Yesterday's accident follows a summer of accidents in road tunnels around Europe, three in Austria alone. At least 24 Polish pilgrims bound for Rome were injured after an accident in the Reigersdorf Tunnel in southern Austria in August. Eight people were killed in two separate accidents in Austrian tunnels earlier that month.
A recent German survey of 16 popular European road tunnels rated only five with good or very good security. The safest tunnels were the Farchant Tunnel in southern Germany and the Kaiser-mⁿhlen Tunnel in Vienna.
The Monrepos Tunnel near Zaragoza in Spain had "very poor" security, according to the survey, with no fire-control measures or accident bays.
Motoring groups in Germany and Switzerland yesterday called for an urgent overhaul of European road tunnels, with separate tunnels to separate traffic flow.
