A plaque commemorating last year's fire inside the Gotthard Tunnel was unveiled at a ceremony on Saturday.
More than 100 people attended a short service at the southern entry to the main north-south axis through Europe.
Eleven people died in October last year when a fire broke out inside the tunnel following a head-on collision between two trucks about one kilometre from the southern entrance to the Gotthard.
The ceremony was attended by the families of the victims of the fire as well as a number of Swiss politicians.
During Saturday's service, a plaque was unveiled in memory - and inscribed with the names - of the four Germans, two French, two Italians, one Swiss and two Turkish citizens who died in the fire.
The ceremony comes five days before the first anniversary of the accident on October 24, when a wreath is due to be laid at the southern entrance and traffic through the tunnel will temporarily come to a halt in memory of those who died.
swissinfo with agencies