Three employees of the South Eastern Coalfields Limited (SECL), including a mining supervisor, were choked to death in a non-functional tunnel of an underground coal mine in Chhattisgarh's Korba district, a company official said Monday.
The accident took place on Sunday evening in Bagdewa coal mines of SECL, which is a subsidiary of Coal India Limited, when mining work was underway, a senior SECL's officer said.
The victims were identified as mining supervisor Laxmikant Prasad, 42, workers Ramadhar, 35, and Ajay, 33, he said.
Work was underway in the underground mine to approach a new coal patch panel from the existing one.
"In between these two panels, there was an old non-functional panel which was closed earlier after coal reserves had exhausted there. The old panel had to be crossed while approaching the new one," Mr Dwivedi said.
As per information, Mr Prasad entered the non-functional panel where the oxygen level was very low without any safety apparatus and fainted, he said.
In a bid to rescue him, Ajay and Ramadhar went inside and they too fell unconscious, the official said.
Soon after being alerted, the three were pulled out and taken to a local hospital where they were declared dead, he said.
Upon investigation, it was found that there were no harmful gases inside the closed panel but there was deficiency of oxygen that resulted in their death, he said.
The officer said it was known to all workers that there was oxygen deficiency in the closed panel and without taking due precaution it was not permitted to go there.
"Ventilation was sufficient in the existing working panel," he said.
"Why he had gone to that place which had oxygen shortage without any safety apparatus, it was not immediately known," the official said.
He said SECL's employees were aware that they had to cross the prohibited panel while approaching the new panel for which additional safety arrangements were being made.
The SECL ordered an internal inquiry into the incident and the Directorate General of Mines Safety was also conducting an independent probe into it.
A case was registered at the Bakimongra Police Station in connection with the incident and the police also launched a probe into it.
Chhattisgarh's chief minister-designate Bhupesh Baghel expressed condolences over the death of the three workers and announced a compensation of Rs 75,000 to the kin of each of the deceased.