# NHPC flagged methane risk months before Sikkim tunnel blast 2026-08-13T07:47:35+00:00 | Governance | Indian Opinion Desk Corroboration: 1 independent outlet NHPC Ltd had flagged methane as a risk at its Teesta VI hydropower project in Sikkim months before a methane explosion in an under-construction tunnel killed 25 workers on July 20, documents on the company’s website show. The Hindushan Times reports that an NHPC document from January 14 records a sudden leak of flammable methane gas during heading excavation at HRT Face 4A, which caused burn injuries and suspension of work. A subsequent safety audit by CSIR-CIMFR recommended strict implementation of handheld methanometers and continuous monitoring. A tender for calibration of three such units was issued on June 17, but the documents do not clarify if all recommendations were implemented before the blast. An expression of interest issued just 10 days before the explosion sought expert agencies to address methane gas and other challenges. ## Coverage - hindustantimes.com Tags: CSIR-CIMFR, hydropower, methane, NHPC, safety, Sikkim tunnel blast Canonical: https://indianopinion.org/nhpc-flagged-methane-risk-months-before-sikkim-tunnel-blast/ License: Summary and commentary (c) Indian Opinion, reusable with attribution. Facts belong to the linked sources. Cite: https://indianopinion.org/nhpc-flagged-methane-risk-months-before-sikkim-tunnel-blast/#story-in-brief Review state: restored archive article, accurate at time of publication, not offered to search indexes.