Gas halts rescue of trapped workers in India tunnel

Toxic gas prevents rescue teams from reaching 13 workers trapped in a hydroelectric tunnel that collapsed in India after a gas explosion that occurred two days ago and killed 12 workers.

The explosion was triggered by a buildup of methane gas and tore through the tunnel at the 500-megawatt Teesta Hydroelectric Project in the northeastern Himalayan state of Sikkim on Monday.

Authorities found the bodies of 12 workers who died in the tunnel about 40 kilometers south of the provincial capital Gangtok.

Administrative officer Anupama Tamling said rescue teams equipped with special breathing equipment and night vision equipment had difficulty entering the tunnel due to accumulation of gas and water.

The Teesta River basin, where the hydropower project is being built, lies in a seismically active region marked by young, brittle rock formations full of cracks and underground pockets that can trap ancient gases.

Fragile mountains, seismic activity and unpredictable underground conditions make tunnel projects in the region particularly risky, experts say.

In February, an explosion at a coal mine in the neighboring state of Meghalaya killed 18 workers.

A tunnel section collapsed in the northern state of Uttarakhand in 2023, trapping 41 workers for 17 days before being rescued.