Following the event that occurred yesterday morning at the Vernasca plant, we inform you that it was caused by the formation of a clog in the first few meters of the clinker kiln. The kiln was being restarted after the shutdown. As a result, once the blockage was cleared, the accumulated raw material - in jargon "meal" - quickly slid towards the kiln head. 
This situation resulted in the release of air and "meal" dust rising upwards and therefore clearly visible from outside. It is believed that, given the granulometry of the material, the radius of the meal dust fallout was close to the plant.
We wish to inform you that ARPA promptly intervened for the appropriate checks and the company promptly notified the relevant authorities.
From a strictly technical point of view, the anomaly lasted about 20 minutes, within which time all the procedures to verify and contain the malfunction were implemented.
Being aware of the inconvenience created by the event, we wish to apologize to the communities of the nearby municipalities.
We commit ourselves to make sure that such unpleasant events never take place again.