The Simplon tunnel, a key north-south rail link between Switzerland and Italy, closed by a fire on a freight train, will not reopen until at least midday Saturday.
Officials had hoped to open the undamaged parallel tube on Friday. But thick smoke from the tunnel in which the accident took place early on Thursday morning is blowing into the other tunnel, and the fire is still smouldering.
“The situation is still not totally under control,” Jean-Louis Scherz, a spokesman for the Swiss Federal Railways (SBB), told the Swiss news agency on Friday afternoon. Fire officers are at the scene.
The tunnel’s two parallel tubes are linked by transverse tunnels every 200 metres, through which the smoke is reaching the undamaged one, making it unusable.
The affected tunnel is reported to have suffered “major” damage, which will take several weeks to repair, according to initial assessments. The SBB said on Thursday that the roof lining could collapse, the rails had probably been distorted, and other infrastructure melted.
Bus services are being laid on for passengers, over the Simplon and the Great St Bernard passes. The Simplon pass road was reopened to traffic on Friday morning after having been closed for a day because of smoke billowing out through the tunnel’s air vents.
Travellers are being advised to take alternative routes where possible. However, the long Whitsun holiday weekend means that all services south are heavily booked and there is little spare capacity.
The fire broke out in the sixth wagon of a train carrying household goods made of steel and porcelain from Italy to Germany. No-one was hurt, apart from a few people who suffered minor smoke inhalation. The flames eventually spread to the following nine wagons because of the immense heat inside the tunnel.
The engine and first five wagons were moved to the Swiss exit of the tunnel at Brig on Thursday.
The cause of the fire is still unknown.
swissinfo.ch and agencies