Lago di Pontesei

The dam originally formed a much larger area, which reached the confluence with the Maresón torrent in the Pónt of Péez.

Preceded by numerous warning signs, including the formation of cracks along the roadway bordering the reservoir, on the morning of March 22, 1959 a landslide, with an estimated volume of about 3 million cubic metres , it broke away from the slopes of Mount Castellin and Spiz, on the left bank of the lake, on a front of 500 meters and fell in two to three minutes, partially filling the lake. Although the basin was 13 metres below the full load level the landslide caused a wave that overcame the dam and overwhelmed Arcangelo Tiziani, a worker of a construction company, who was carrying out the construction of the power plant downstream of the dam, whose body was never found. The accident is considered to have foreshadowed the Vajont dam disaster thanks to the similar way it unfolded, and, while the Vajont Dam was built in neighbouring Longarone, it was observed with great concern.

Wikipedia