The Xe Pian-Xe Namnoy Dam was being built by Korea-Laos joint venture Xe-Pian Xe-Namnoy Power Company. The missing include 50 people in Ban Mai in Sanamxay district.
The PNPC joint venture, which began work in March 2012, is made up of SK Engineering & Construction (24%), Korea Western Power (25%), Ratchaburi Electricity Generating Holding (25%), and Lao Holding State Enterprise (26%).
Local reports say that SK Engineering & Construction had discovered damage to an auxiliary dam the previous day and had immediately notified the authorities and begun evacuating nearby villagers.
According to the government’s Lao News Agency, the project has an estimated cost of US$1.02bn (£775m) and is the first build-operate-transfer (BOT) project to be undertaken by the Korean companies in Laos.
Construction began in February 2013 and commercial operations had been expected to begin in 2018.