Three daily wage labourers on Wednesday died after inhaling toxic gas while cleaning a sewage treatment plant of a local civic body in Thane district of Maharashtra, a police official said on Thursday, adding the deceased, identified as Muzaffar Moulik (24), Rafique Mandal (50) and Mofjum (18), had no formal training in sewage cleaning.
According to an official at Thane rural police's control room, the incident was reported at Mira Road area while the labourers were cleaning a chocked valve in a chamber of the non-operational sewage treatment plant.
One of the labourers collapsed out of suffocation after he climbed down into the sewage treatment plant to clean it, he said.
Two more labourers later went inside to check their colleague, but they also inhaled toxic gas and died, he said.
Another 17-year-old labourer was undergoing treatment at a hospital after he had inhaled the toxic fumes, the official said.
The labourers were not trained in such cleaning operations and were hired by a civic contractor from near the Mira Road railway station for the cleaning work, he said, adding they were not provided with any protective gear like masks.
The bodies were sent to a local hospital for post mortem and a probe was underway, the official said.