KOLKATA: Two workers died after entering a septic tank in West Bengal's Hooghly district on Saturday, police said.
The deceased have been identified as Ganesh Manna and Subrata Das, both aged 40 years, police added.
"The two workers had come to remove a construction plank inside the septic tank in a house in Singur's Ratanpur village. The tank was built two to three months ago," police said.
Quoting housewife Chandana Maiti, police said one of the workers first entered the tank after opening the lid while his colleague waited outside.
"When he did not get any response from his colleague after waiting for a few minutes, he too entered the tank. But none of them came out," police said.
Though fire brigade personnel and police rescued the workers and rushed them to a hospital, both were declared dead by doctors, police added.
Police have started an investigation into the incident.
A fire brigade officer suspected that methane gas might have accumulated inside the tank, which could have claimed their lives. Methane gas is a colourless and odourless gas and can be deadly, an expert said.