Gangtok, July 21, July 21 -- At least 10 people were killed and several others are feared trapped after an under construction tunnel of the Teesta Stage VI Hydroelectric Project collapsed in Sikkim's Namchi district on Monday. The incident was triggered by a landslide, with officials suspecting that a methane gas explosion inside the tunnel worsened the collapse. The debris blocked the tunnel entrance, making rescue efforts extremely challenging. Teams of the National Disaster Response Force, State Disaster Response Force, police, and other emergency agencies have launched a massive rescue operation to locate and evacuate the trapped workers. However, continuous rainfall has severely hampered the operation by causing further instability i...