Updated

Switzerland's main passenger rail connection to Italy has been cut for at least a month because of a rockslide in the Alps that has left one man missing.

Swiss railway company SBB says the Gotthard line is blocked after a massive rock wall collapsed near the village of Gurtnellen, 60 kilometers (37 miles) south of Zurich, on Tuesday.

Three workers were buried in the rockslide. Two of the men were rescued, but one remains missing.

SBB said Wednesday that travelers will have to use replacement buses or the Simplon rail tunnel to get from northern Switzerland to Italy.

Affected connections include the international line from Zurich and Basel to Milan, in Italy.

A new railway tunnel underneath the Gotthard mountain pass is under construction and will be completed by 2016.