The explosion was so strong it caused the collapse of masonry and concrete floors of the sewage station building, nearly destroying it completely, says the report. Several brigades of fireman and emergency services worked for several hours to extract workers from the rubble.
On November 8, the regional prosecutor office said that the main reason for the explosion was an accumulation of methane gas which had built up in the building during the repair operations.
Cigarette the likely cause
Russia’s Investigative Committee opened a criminal case under charge of violation of labour safety requirements, negligently causing the death of a person. However, according to Russian law enforcement officers, the main reason for the incident was a violation of labour safety rules by the injured employees themselves.
“Methane can explode only when there is an open flame source. Workers were using no special equipment and had only unscrewed two bolts of a manhole cover and not even picked it up when the explosion took place,” explained the official spokesperson for the Investigative Committee, Larisa Boldyreva.
Therefore the most likely cause of the explosion was a lighted cigarette, she added.
“Workers did not use any tools that could have caused inflammation, such as a gas burner or a blowtorch. Most likely, one of them lit a cigarette and threw the butt in the room unquenched, which ultimately led to an explosion,” stated head of the Omsk inter-district investigatory department, Nikolai Anoshkin.
According to preliminary information, operation of the sewage system has now been fully restored. Meanwhile, the government of Omsk Oblast stated it had taken control of the incident and would monitor the investigation process.
Farm owner Prodo Group has initiated an internal investigation into the case, refusing to make any comment until it is completed.
This was not the first serious incident at the company’s Siberian poultry farm.
On June 6, a worker was seriously injured after falling off scaffolding. Investigations revealed the reason for this incident was violation of safety rules by the head of the construction crew, who has been arrested. A court trial is currently taking place.
Prodo Group owns nearly a dozen meat processing facilities, and poultry and pork farms in several regions of Russia. Founded in 2004, it is one of the largest companies in the Russian food market.