Methane blast collapses tunnel killing 7 in Sikkim; 18 remain trapped

Gangtok: At least seven workers were killed, and 18 remain trapped after a landslide triggered by a methane gas explosion inside an under-construction tunnel in Sikkim's South Sikkim district on Monday. Rescue operations are underway under the supervision of the National Disaster Response Force (NDRF) and other emergency agencies.

The incident occurred at around 3.09 pm inside the Samardung tunnel, where 25 workers, including employees of the National Hydroelectric Power Corporation (NHPC), were trapped. District authorities have confirmed seven deaths, while the collapse sealed the tunnel entrance, severely hampering rescue efforts.

The tunnel is being constructed by Pargel Engineering Company as part of the Teesta Stage VI hydroelectric project in Namchi district. Officials said methane gas, naturally released from underground rock formations, had accumulated over a stretch of about 1.5 kilometres inside the tunnel. An explosion reportedly occurred while efforts were being made to vent the trapped gas, triggering the landslide that blocked the entrance. Although some workers managed to escape immediately after the incident, many remained trapped inside.

Rescue operations have been complicated by continuous gas leakage, low oxygen levels, poor visibility and the tunnel's narrow passages. Fire and Emergency Services were forced to abandon initial rescue attempts after personnel experienced breathing difficulties because of the methane and oxygen deficiency.

The NDRF, the State Disaster Response Force (SDRF) and Sikkim Police are continuing rescue operations despite the hazardous conditions.