MUMBAI: Three workers, who had entered a choked sewage drain near the service road between Bhandup and Kanjurmarg on the Eastern Express Highway to clean it, died of suffocation early on Sunday. They did not have any safety gear on and probably died after inhaling the poisonous gases.

The incident occurred around 2.30am when the three victims—Sameer Pradhan (32), Daneshwar Swin (30) and Rajkishore Biswal (47)—entered the closed drain to carry out cleaning work, said the Kanjurmarg police. All of them lived in shanties at Bhandup (E).

Four other labourers , who had followed the trio, managed to get out after seeing the three stuck in and breathless.

According to the BMC, the labourers hired on contract were cleaning the sewage line to connect the drain network leading to the Bhandup sewage treatment when the incident occurred. Civic officials said they had told the contractor to stop the work on Saturday evening. But the contractor went ahead and deployed the men at night. The BMC is going to take action against the contractor, said a senior civic official.

The four labourers somehow managed to get out while the three others were stuck 15-metres inside. “On hearing their screams, passersby called the fire brigade. The three stuck workers were rescued after nearly an hour,” said a police officer.

The labourers were rushed to Rajawadi hospital, where they were declared dead on admission. Dr Anil Chopde, senior medical officer of Rajawadi Hospital, said all three were brought dead early on Sunday. Initially, the police registered a case of accidental death. At the time of going to press, they were in the process of registering an FIR against the supervisor or contractor for negligence that cost the lives of the three labourers. Police are also awaiting the post-mortem report to know the type of gas the three inhaled.

“Statements of the other labourers were recorded which clearly show that the agency assigned the cleaning work did not follow the basic safety measures. The workers were not provided with safety gas masks while entering the enclosed drain,” said the investigators.

