The location of Tauredunum has long been debated. Among other alternatives, it has been suggested that it was situated near the Bois Noir at Saint-Maurice or at the foot of the Pic du Blanchard near Saint-Gingolph. The landslide is now thought to have occurred on the mountain of Le Grammont, near Les Evouettes at the point where the Rhône empties into Lake Geneva. Such collapses, known as éboulements or bergfalls, are not uncommon in the Alps; in October 1963, the collapse of the side of Monte Toc in Italy caused 260 million m³ of debris to fall into the lake behind the Vajont Dam, sending a wave of water into the valley that killed up to 2,500 people. Mountainside collapses have caused similar though smaller lake tsunamis in at least three lakes in Switzerland - Lake Lucerne, Lake Lauerz and Lake Brienz. The danger is recognised by Switzerland's Federal Office for Civil Protection, which takes the risk of landslide-caused tsunamis into account in its disaster planning. Certain mountains, such as the Rigi and the Bürgenstock, present more of a risk. It is not uncommon for large boulders to fall off the Bürgenstock into Lake Lucerne, though this presents little risk of a tsunami because of the relatively low amount of energy released in such falls.