stylistic:style_transfer, structural:expansion
The Vajont Dam or Vaiont Dam is a disused hydro-electric dam in northern Italy. It is one of the tallest dams in the world, with a height of 262 m (860 ft). It is in the valley of the Vajont (river) under Monte Toc, in the municipality of Erto e Casso, 100 km (62 mi) north of Venice. The dam was conceived in the 1920s and eventually built between 1957 and 1960 by Società Adriatica di Elettricità, at the time the electricity supply and distribution monopoly in northeastern Italy. The engineer was Carlo Semenza (1893–1961). In 1962, the dam was nationalized and came under the control of ENEL as part of the Italian Ministry for Public Works. On 9 October 1963, during initial filling of the lake, a landslide caused a megatsunami in which 50,000,000 m⁳ (1.8×10⁹ cu ft) of water overtopped the dam in a wave of 250 m (820 ft), bringing massive flooding and destruction to the Piave Valley below, destroying several villages and towns, causing an estimated 1,900 to 2,500 deaths. The dam itself remained almost intact and two-thirds of the water was retained behind it. This event occurred after ENEL and the Italian government concealed reports and dismissed evidence that Monte Toc, on the southern side of the lake, was geologically unstable. They had disregarded numerous warnings, danger signals, and negative appraisals. Underestimating the size of the landslide, ENEL's attempt to safely mitigate any landslide by lowering the level of the lake came too late, when disaster was almost imminent.