[2] Construction of the earth-filled Saddle Dam D near Paksong,[5] part of the $1.2bn (£915m)[6] hydroelectric project by Xe-Pian Xe-Namnoy Power Company (PNPC),[6][note 1] was begun in 2013.
[13] The dam, close to the Cambodian border,[6] was intended to operate to a capacity of 410 megawatts, and earn revenue for the government by exporting 90% of the electricity produced to Thailand,[6][17] which is more economically prosperous and developed compared to Laos.
[18] Environmental pressure groups have long been critical of the Laotian government's ambitions regarding hydroelectric power, which have involved building multiple dams on the Mekong as well as on its tributaries.
Neighboring countries, like Cambodia and Vietnam that are downstream from the dams and rely heavily on the Mekong[19][20] for fishing,[21] food, agricultural irrigation, transport, tourism and cultural traditions,[19][20] have expressed concern that Laos' hydroelectric ambitions could "disrupt vital ecosystems and their own river systems".
[15] Furthermore, the Agence France-Presse (AFP) reported that it had obtained documents showing that "11 centimetres of subsidence was found at the centre of the dam" as early as the previous Friday.
[15] On 11 September 2017, the reservoir for a dam under construction on the Nam Ao River in Phaxay district, Xiangkhouang Province collapsed after heavy rains in the area.
[24] In December 2016, the Xekaman 3 dam in Dak Cheung District, Sekong Province, had to be shut down after six years of usage due to damage in water tunnels.
[25] The dam collapse occurred around 8 p.m.[17] on Monday 23 July, and caused immediate flash flooding through the villages[11] of Yai Thae, Hinlad, Ban Mai, Thasengchan, Tha Hin, and Samong, all in Sanamxay district.
[6] The CEO of one of the companies involved stated that "[it] was fractured and the water had leaked to the downstream area and down to the Xe-Pian River which is about five kilometres from the dam".
[2][31] Government agencies and the power company jointly commenced a rescue and evacuation of villages still in danger,[11] amid rising water levels.
[11] The Prime Minister of Laos, Thongloun Sisoulith, suspended his immediate meetings and travelled in person to the site,[11] as did the President and board of SK E&C.
[32] The neighbouring Asian countries of China,[33] Malaysia,[34] Philippines,[35] Singapore,[36] Thailand[37] and Vietnam[38] have also expressed readiness to provide any assistance needed by Laos.
[43] Singapore Armed Forces (SAF) delivered S$280,000 in flood relief supplies on Thursday evening while officers from SCDF will arrive on Friday.
[48] The Vietnamese People's Army (VPA) sent a contingent team of 100 officers, including medics and rescue vehicles to assist in relief efforts.