Dibrugarh, Nov. 4: A ball of fire, fuelled by highly combustible methane gas, killed one worker and injured 18 others at Ledo colliery in Tinsukia district early this morning.

The mishap took place at around 5.45am in an underground mine operated by Coal India Limited at Ledo, located on the easternmost tip of Assam.

The only casualty was reported at the hospital of the Indian Oil Corporation (Assam Oil Division) in Digboi — 25 km from the coalfields — where two of the injured were admitted. The dead miner has been identified as Putul Doimari. The condition of another injured person in hospital, L. Pollaiya, is also stated to be serious.

Eight others have been admitted to Assam Medical College and Hospital (AMCH) here and six to the Coal India Limited (CIL) hospital at Margherita, 7km away. Three others who had sustained minor injuries were discharged after first aid at the CIL hospital. The condition of two of the injured at the AMCH was stated to be serious.

“Altogether 39 miners were at work when the accident occurred,” CIL’s North East Coal Fields (NECF) manager (public relations) Ranjit Kumar Dutta said over telephone.

CIL mining engineer Anil Kumar Bharali said that in deep-pit mining, extraction of coal is often accompanied by release of gases like carbon monoxide and methane. “We take precaution by sealing all possible areas on the walls of the tunnels from where the gases might escape. In today’s accident, some gas escaped, leading to the accident,” he added.

Another CIL official said that most of the accidents in coal mines are caused by methane combustion.

Nirmal Chand, one of the injured under treatment at CIL hospital, said that he saw “a ball of fire” rushing towards him from the depths of the tunnel which is dug at an incline.

”I saw many of my co-workers engulfed in the blaze and smoke. Screams for help and agony filled the tunnel. Some of them rushed towards the opening,” he added. A part of the tunnel’s wall also collapsed, another injured S. Sommaiyya said.

Rescuers struggled against black fumes, to bring out the workers, with the help of the rail-trolleys, to safety.

All the 39 workers had entered the mine at 11pm the previous night and their shift was scheduled to end at 7am.

“The rescue operation was carried out with the help of the Tinsukia district administration and Margherita sub-divisional administration. We managed to rescue the people in a very short time,” Dutta said.

The CIL official said that they have taken the matter very seriously and an internal inquiry has been ordered.

A high-level team from the department of mines, government of India and two CIL directors will arrive from Calcutta tomorrow for an assessment and conduct the inquiry.

Tinsukia deputy commissioner K.K. Dwivedi, chief general manager of NECF Anil Kumar Bora and the sub- divisional officer (civil) of Margherita Partha Pratim Mazumdar also inspected the site.

The CIL has three mines at Ledo, apart from two open-cast coalfields. The North East Coal Fields annually yield just over 1 million tonnes of coal. The mine where the accident occurred has an annual output of around 45,000 tonnes.

Today’s accident was the third in these coalfields. In 1979, 19 miners were killed when part of a tunnel caved in while in 1993, nine workers were killed in a similar accident.