Three engineers were killed at a state-run hydropower project in Himachal Pradesh's remote Spiti valley when a valve at the plant burst.
The incident occurred on Sunday night at the 2-MW Rongtong hydropower project plant near Kaza town, which is located some 420 km from the state capital.
Sanjay Kumar, Vijay Kumar and Sanish were killed while they were fixing the new turbine.
Official sources said the burst of the main inlet valve, which controls the water supply to the turbine, led to the death of the engineers. They were crushed under the turbine.
Two of them were from the state electricity board, while the third was from a private company in Noida, Uttar Pradesh.
The hydropower plant, which is more than 20 years old, supplies electricity mainly to Kaza town. The plant has been closed for over four years as most of the machinery is outdated. It has been going under overhauling for the past few months.
Chief Minister Virbhadra Singh will visit Kaza on June 19 for the plant's inspection.