The toll from flash floods in the Teesta river in Sikkim rose to 14 on Thursday, ANI reported. At least 26 persons have sustained injuries.

The Sikkim government said that 102 persons are currently missing, including 22 Army personnel.

The floods were triggered by a glacial lake outburst in northern Sikkim’s Lachen valley. Chief Secretary VB Pathak said that the Lhonak lake breached its embankment and discharged large volumes of water into the Teesta, raising its levels.

The chief secretary added that 12 to 14 people working at the Teesta Stage 3 Dam in Chungthang are stranded in the tunnels, according to ANI. More than 3,000 tourists are feared trapped in the state as well.

Sikkim’s biggest hydropower project Sikkim Urja has been washed away, along with the 200-metre-long bridge connecting the powerhouse.

The state government has declared the floods a disaster under the Disaster Management Act.

According to Anit Thapa, Chief Executive of the Gorkhaland Territorial Administration, the flash floods have affected more than 5,000 people. The Gorkhaland Territorial Administration is a semi-autonomous council for the Darjeeling and Kalimpong districts of West Bengal.

The state government said that 14 bridges have collapsed due to the floods, reported Hindustan Times. The NH10, the main link between Sikkim and the rest of the country, was washed away entirely near the Likhuvir-Setijhora stretch. Urgent repair work will be carried out once the water subsides.

The army and National Highways and Infrastructure Development Corporation Limited have assembled Bailey bridges – a type of portable, pre-fabricated, truss bridge – for necessities to reach the state from West Bengal’s Siliguri.

The state government has set up 18 relief camps in Singtam, Rangpo, Dikchu and Adarsh Gaon, areas that have suffered the most damage.

Prime Minister Narendra Modi took stock of the situation on Wednesday and assured Chief Minister Prem Singh Tamang of all possible support. “I pray for the safety and well-being of all those affected,” he wrote on X.

Congress president Mallikarjun Kharge said that the situation in Sikkim is precarious and urged the Centre and the state government to work together to rebuild the state.

“The Union Govt must recalibrate its strategy in dealing with ecologically fragile Himalayan states and must declare such tragedies, like Sikkim and Himachal Pradesh, as national disasters so that these states get adequate funds to rebuild themselves in a more sustainable manner,” he said in a tweet.

Satellite images of Lhonak Lake

The Indian Space Research Organisation on Wednesday released satellite images, which revealed that nearly 105 hectares of the Lhonak Lake was drained out between September 28 and October 4.

While the lake held 162.7 hectares of water on September 17, the volume went up to 167.4 hectares on September 28. On Wednesday, after the outburst, the lake was reduced to 60.3 hectares.

“It is observed the lake is burst and about 105 hectares has been drained out, which might have created a flash flood downstream,” the space agency said.

Satellite images of South Lhonak Lake. Credit: ISRO