A tenant who had just moved into his flat in a three-storey building went down to the boiler room to open the gas valve to his flat. He opened a valve but did not know that the other end of the copper pipe was not capped. Natural gas leaked out, resulting in an explosion that caused the building to collapse. Ten people were injured, with one of them seriously hurt. All were taken to hospital by the firefighters. The other residents were rehoused.
An investigation by the authorities found that the valves in the boiler room were improperly identified. Each flat was investigated, with special attention being paid to the gas pipes leading down to the boiler room. The gas tanks connected to the cookers in the flats were inspected, but nothing unusual was found. When the last flat was inspected, it was found that the gas pipe in it led to an open valve that was not connected to anything. In addition, the valve had a defect: when opened halfway, the flow rate was higher than when opened completely.
Following the accident, the inspection authorities for classified facilities issued a number of recommendations, including the need for extending gas inspection reports to rentals.