At least three workers were killed and three others injured in an explosion at a hydroelectric power plant on a reservoir in northern Italy on Tuesday, the authorities said. In addition, six workers were still missing in the evening at the plant on the Suviana reservoir between the cities of Bologna and Florence. According to initial findings, a fire broke out during work on a turbine at a depth of around 30 metres, which led to the explosion. The dam itself was not affected. The fire brigade had great difficulty reaching the site of the accident due to the heavy smoke. The mayor of the nearby…