Chiang Rai tunnel construction accident kills two, seriously injures three

Two people were killed and three others seriously injured when a heavy installation component fell onto them inside a railway tunnel under construction in Chiang Rai province on Saturday.

The accident occurred inside the 3.4km Doi Luang Tunnel, part of the State Railway of Thailand's (SRT) Den Chai–Chiang Rai–Chiang Khong railway project. The tunnel is being built to connect Den Chai district in Phrae province with the border district of Chiang Khong in Chiang Rai province.

Initial reports indicate that the workers were installing equipment, believed to be part of the tunnel's lighting system.

Part of the equipment suddenly detached and fell onto the workers who were standing on a scaffold inside the tunnel.

Two workers died at the scene, while three others sustained serious injuries.

Ambulances were able to enter the tunnel and reach the accident location, where rescue teams retrieved the victims and transported the injured to hospital.

Initial investigations have found that the tunnel excavation had been completed and the structure had been reinforced with a sprayed concrete lining.

Steel framework and scaffolding had been installed along the length of the tunnel to support ongoing work.

Police said a heavy metal installation component, consisting of circular steel rings connected by metal ribs, fell from above and struck the workers below. The impact trapped the victims against the steel framework.

The cause of the accident is under investigation.