This note describes a 70.000 cubic meters landslide of high rich water and organic material loam (80% water, 15% inorganic residue plus 5% organic material). The organic material was formed by grass leaves, carbonized fragments and humified substances. Spicules of sponges and diatoms fragments occur together, proving the existence of an ancient and small lake in the place of the loam accumulation. Humified material and the high water contend caused the decrease of the loam shear strength. The clay mineral of the loam belongs to the caulinite group, but gibbsite is also present. The coarser minerals are quartz, baueritized biotite and partially decomposed feldspar. The loam accumulated in an amphitheater of 13.000 square meters and 8 meters thickness, was liquefied due to the weight of a small fill. The vibration caused by the movement of a tractor was the possible start of the landslide, who runned more than 500 meters, covering 60 houses and killing 17 people.
