SHILLONG, July 11: Three persons died of carbon monoxide poisoning while cleaning an underground water reservoir while two more died during a rescue attempt at Dongmadan Lane 4, Lapalang, on Friday evening, with officials confirming that toxic fumes from a diesel pump caused the tragedy.
Sub-Divisional Officer (SDO) of the Water Resources Department, Larrypor Roy Nongbri, on Saturday confirmed that the victims died after inhaling carbon monoxide emitted from a diesel pump used to pump out water from the underground reservoir. He explained that carbon monoxide is a highly poisonous gas that rapidly displaces oxygen in confined spaces, causing victims to lose consciousness within a very short time.
According to Nongbri, a person exposed to the gas under such conditions can become incapacitated in as little as 30 seconds, leaving virtually no opportunity to escape. Nongbri also pointed out that the underground reservoir was approximately 33 feet deep, making it an extremely hazardous confined space with poor ventilation where toxic gases could easily accumulate.
The tragedy occurred on Friday evening when four men entered the underground water reservoir inside a residential compound to carry out cleaning work. During the operation, they were overcome by the poisonous gas. While one worker managed to climb out and raise the alarm, the remaining three remained trapped inside. Hearing the cries for help, two other men entered the reservoir in an attempt to rescue those trapped. However, they too succumbed to the toxic fumes, taking the death toll to five.
The deceased included three Khasi workers – Pynskhemlang Mawthoh (22) and Rapborlang Nongspung (35), both residents of Thangsning, Smit, and Elka Shadap (25), resident of Umiew Maw-u-Sam, Smit.
Two brothers — Sunil Thakuri (34) and Umesh Thakuri (30) — both resident of Nongrah Dongktieh, Block-5, Shillong, died while trying to rescue the workers.
The bodies were shifted to NEIGRIHMS, where doctors conducted a virtual autopsy using MRI and CT scan imaging after the families declined a conventional post-mortem examination. The bodies were handed over to their respective families on Saturday.
The families of the victims from Thangsning and Umiew, accompanied by village leaders and Mawkynrew MLA Banteidor Lyngdoh, received the bodies before taking them to their respective villages for the last rites.
Water Resources Department officials and Rynjah police station personnel visited the site on Saturday and initiated an inquiry into the incident.
East Khasi Hills SP, Vivek Syiem informed that a case has been registered at Rynjah Police Station as Rynjah PS Case No. 106(1)/2026 under Section 125(a) of the Disaster Management Act, 2005.
The Sector Magistrate has lodged an FIR against the owner of the property and the contractor, alleging negligence in connection with the incident.
Lapalang Rangbah Shnong Pyndap Sohtun said the Dorbar Shnong received information about the incident at around 7.30 pm on Friday and immediately rushed to the spot along with the Assistant Rangbah Shnong.
According to Sohtun, the workers were in the final stage of cleaning the reservoir by pumping out the remaining water when the accident occurred. He suspected that the diesel pump used inside the confined underground space resulted in the accumulation of carbon monoxide or depletion of oxygen, leading to the fatal incident.
He said no one dared to enter the reservoir after the two rescuers were also overcome by the gas. The local MLA, Deputy Commissioner Abhilash Baranwal, magistrates, doctors and other authorities were immediately informed, following which rescue and recovery operations were launched.
The Rangbah Shnong said the Dorbar Shnong does not permit the digging of private water reservoirs or wells as the locality already has an adequate water supply. However, many residents continue to excavate underground water reservoirs because Lapalang is a catchment area where groundwater is easily accessible. He urged the state government to formulate comprehensive guidelines governing the excavation, maintenance and cleaning of underground water reservoirs and wells, including mandatory safety protocols for work in confined spaces, to prevent similar incidents in future.
Sohtun further said the Dorbar Shnong, in coordination with the Public Health Engineering (PHE) Department, is working to strengthen water supply in the locality through the Jal Jeevan Mission (JJM) so that residents need not depend on private underground reservoirs.
