Three sanitation workers in Ghaziabad suffocated to death on Sunday inside a 40-feet deep main pumping station plant or MPS they had climbed down into for cleaning, police said.
Loni Deputy Superintendent of Police Durgesh Kumar said the incident took place in the Dabur Talaab Colony in Ghaziabad's Loni area where the MPS is located.
He said the three fell unconscious after inhaling poisonous gas inside the facility and died later, he said.
Mr Kumar said the three deceased employees have been identified as Bulbul, Mahesh and Roshan (all in their late thirties) and their bodies have been sent for postmortem.
He said the three bodies were recovered after a National Disaster Response Force team reached the spot.
The police said a complaint has been registered against a company for allegedly not providing proper apparatus for the sanitation workers.