Billions of cubic metres of water swept away homes in six villages in southern Laos yesterday after a hydropower dam under construction by a South Korean company collapsed.
Hundreds are missing and 24 are confirmed dead, ABC reports.
More than 6,600 people in the Sanamxay district are now homeless, according to state Lao News Agency.
The company building the dam, SK Engineering & Construction, said heavy rain and flooding caused the collapse.
"We are running an emergency team and planning to help evacuate and rescue residents in villages near the dam," a spokesman told Reuters.
The Xepian-Xe Nam Noy hydropower dam collapsed at 8pm Monday, releasing 5 billion cubic meters of water, the state news agency said.
Prime Minister Thongloun Sisoulith suspended government meetings and took his cabinet to the area to monitor rescue and relief efforts, the agency reported.
Reuters comments that Communist Laos, one of Asia’s poorest countries, is land-locked and aims to sell power to neighbouring countries with a series of hydropower dams.
Environmental groups have raised concerns about Laos’ dam building.
Construction of the dam, which is estimated to cost $1.02bn, began in 2013 and it was expected to start generating power this year, the state news agency said.
The developer of the 410MW power project is Xe Pian-Xe Namnoy Power Company (PNPC), which is a joint-venture formed in 2012 by SK Engineering and Construction, Korea Western Power, Thailand’s Ratchaburi Electricity Generating Holding, and Lao Holding State Enterprise.
It is the first build-operate-transfer (BOT) project to be undertaken by South Korean companies in Laos.
PNPC had planned to export 90% the power to Thailand, said Reuters.
Ratchburi Electricity Generating Holding said in a statement the dam, which it referred to as ‘Saddle Dam D’, was 770m in length, 16m high, and 8m thick, Reuters reported.
Campaign group International Rivers told Reuters the accident exposed "major risks" associated with some dam designs that are "unable to cope with extreme weather conditions".
"Unpredictable and extreme weather events are becoming more frequent in Laos and the region due to climate change," the group said in an emailed statement.
"This also shows the inadequacy of warning systems for the dam construction and operations. The warning appeared to come very late and was ineffective in ensuring people had advance notice to ensure their safety and that of their families," the group said.
- Updated 25 July for latest casualty toll
Image: Villagers in Sanamxay district boarded boats to escape the flood (Lao News Agency)