On Wednesday evening, a 30-tonne block of Nagelfluh rock broke loose above the Franzosenloch in Walchwil, cutting a swathe through the forest and damaging Hinterbergstrasse.

No one was injured as there was no one on the road at the time of the incident. Hinterbergstrasse is expected to remain closed until the weekend.

The conglomerate block, measuring around 25 cubic metres, broke loose from the loose soil on the steep slope, crashed through the forest, hit Hinterbergstrasse and came to a halt slightly below in the loose forest soil. On its way, it collided with several thick trees, which it smashed but which took up a considerable amount of its energy before it finally reached the road, leaving deep impact marks.

An initial assessment indicated that there is currently no acute danger. Further investigations are currently being carried out. Provided these do not reveal any additional risks, the road will be provisionally repaired by the weekend and reopened to traffic. Canton of Zug

Images: Office for Forestry and Wildlife