Two geologists working for the Italian-Thai Development Co Ltd in Chiang Mai were killed after an under-construction water tunnel collapsed in Mae Taeng district of Chiang Mai this morning.
The tunnel is under excavation to divert water from Mae Ngad Somboonchon dam to Mae Kuang Udomtara dam.
The geologists, Pratomporn Siriwat, and Pratchayawat Wasu-anan, were in the tunnel to inspect the soil.
As both walked along the 4.2 metres wide tunnel, the tunnel collapsed and buried them underneath.
Rescue workers managed to pull them out after they were already dead.
Authorities said they believed the two geologists went to inspect the tunnel on untimely period as supporting steel structures have not yet been put in to support the soil ceiling.
They said since the excavation of rocks used explosives, it should allow enough time for soils to fall and then build supporting concrete panel in the excavated section.
Actual cause of the collapse is now under investigation by the company and the police.
The 11.5 billion baht underground water tunnel is 22.9 kilometres long with construction starting in April 2015 and ending in August 2019.
Source: Thai Public Broadcasting Service (Thai PBS