MOSCOW, November 6. /TASS/. The investigators have initiated a case of negligence following a fire in the Polygon nightclub in Russia’s Kostroma that killed 13 people, the press service of the Investigation Committee said in a statement on Sunday.

"Based on the results of a procedural inspection on the fact of negligence that caused the death of two and more people out of negligence, a criminal case has been initiated on the signs of a crime under Part 3 of Article 293 of the Criminal Code of the Russian Federation," the statement reads.

The investigators suggest that no inspections in the building of the nightclub have been carried out by responsible officials for a protracted period of time. Neither were they planned. "The failure to fulfill supervisory authorities in the firefighting area caused a long-term absence of control over observance of fire safety requirements in the building, due to which the main goal of the fire protection service as organization and implementation of fire prevention activities at the facility was not met," the Investigation Committee explained.

That brings the number of cases on the fact of a nightclub fire the Committee is investigating to four. Earlier, cases were launched for manslaughter, breach of fire safety rules and provision of services failing to meet safety requirements.

The fire broke out at the Polygon nightclub late on Friday, spreading across 3,500 square meters. According to the latest information, 13 people died and nine were injured. The fire presumably started after a patron fired a hunter’s flare gun inside.