The Indian tunnel blast that struck an under-construction hydroelectric project in Sikkim has left at least 22 people dead, after authorities recovered seven more bodies from the site on Thursday. The state government confirmed the updated toll as recovery operations continued at the tunnel, four days after the explosion first trapped dozens of workers underground.
Indian Tunnel Blast Toll Climbs as More Bodies Recovered
The Sikkim state government said the additional bodies were pulled from the tunnel on Thursday, raising the confirmed death toll from the blast to 22. The steady rise in fatalities over the course of the week reflects the difficulty rescue teams have faced in accessing the affected section of the tunnel, where conditions have made recovery work slow and hazardous.
Officials have not indicated how many victims may still be unaccounted for as search efforts continue, though the scale of the confirmed toll already marks one of the deadliest industrial accidents to strike India’s hydroelectric sector in recent years.
Sikkim Hydroelectric Project Site of Monday’s Explosion
The incident took place on Monday at a project run by the state-owned National Hydroelectric Power Corporation on the Teesta river, near the village of Samardung in Sikkim state. The under-construction facility forms part of India’s broader push to expand hydroelectric capacity in its mountainous northeast, a region where several large-scale power projects have been developed in recent years.
At the time of the explosion, the tunnel was occupied by 25 workers and officials associated with the National Hydroelectric Power Corporation, all of whom became trapped once the blast occurred.
Teesta River Tunnel Filled With Toxic Gases
Investigators believe the explosion was caused by methane that had either become trapped within surrounding rock formations or was released from them during construction work. The resulting blast filled the tunnel with dense fumes and toxic gases, sharply reducing the chances of survival for those caught inside and complicating early rescue attempts.
The presence of toxic gas in the confined space has remained a central challenge for recovery teams throughout the operation, requiring specialised equipment and protective measures to allow personnel to safely re-enter the affected sections of the tunnel.
NHPC Rescue Operations Continue Amid Slim Survival Hopes
Authorities had cautioned earlier in the week that the survival chances of those still trapped inside the tunnel were slim, given the concentration of toxic fumes and the structural risks posed by the blast. Despite this, rescue and recovery efforts have continued without pause since Monday.
In a statement posted on Facebook, the Sikkim state government said rescue operations remained in progress, with specialised teams working in close coordination to locate and recover the remaining victims. The statement underscored the continued commitment of state authorities to the operation even as hopes of finding survivors have diminished.
What Comes Next
With the death toll from the Indian tunnel blast now at 22 and recovery work still under way, attention is likely to turn toward establishing the precise cause of the methane buildup and reviewing safety protocols at similar under-construction hydroelectric sites across the region. For now, officials in Sikkim remain focused on the immediate task of locating any remaining victims as the operation on the Teesta river continues into its fourth day.
Published in SouthAsianDesk, July 23, 2026
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