NThe last worker missing after an explosion at a hydroelectric plant in northern Italy was found dead on Friday. The fire service announced that a total of seven people died in the accident on Tuesday. The explosion occurred at the Bargi hydroelectric power plant located at the Suviano dam in the municipality of Camugnano near Bologna in northern Italy.

The exact cause of the accident remained unclear on Friday. Power plant boss Salvatore Bernabei dismissed speculation about potential safety lapses in interviews published on Friday. It is “premature” to comment on the reason, the situation is “very complicated”.

The company had earlier attributed the explosion to a fire in one of the power plant's two units. It erupted during “efficiency improvement work” at the plant.

Four other workers injured in the blast are still in hospital, authorities said. Two of them are still in serious condition. The public prosecutor's office in Bologna has now opened an investigation.

The reservoir is located in the regional park in the Apennines between the cities of Bologna and Florence at an altitude of nearly 500 meters. The power plant is operated by the Italian electricity supplier Enel. According to the authorities, the men who worked for subcontractors on the turbine were involved. The issue of occupational safety has been hotly debated in Italy since the incident. Hundreds of demonstrations took part in Bologna on Thursday for better working conditions at power plants. Unions called for protests.