On the night between 19 and 20 July 1944, partisans of the “Stella Rossa” brigade went to the mill at Ponte Locatello, in the Pian di Setta area, to obtain money from the administrator Anacleto Monti, a known fascist. When he refused and the partisans attempted to force the door, Monti reacted by opening fire. The partisans were forced to flee, but at that moment a column of German soldiers arrived on the road and, believing they were under attack, opened fire on the house. The clash lasted almost the entire night: three German soldiers were killed, while Monti and his wife were seriously wounded.

Nearby, the Piacenti couple, who had taken refuge in their adjacent home, tried to escape, believing the area was no longer safe. She was captured and taken to prison in Bologna, while her husband was caught and killed on the spot.

The following morning, German troops set fire to the Monti house with the injured couple still inside, killing them both.

On 21 July, the partisans struck again in the Mulinelli area, ambushing a car they believed belonged to a fascist doctor. Instead, a German sergeant was killed. This incident triggered an immediate response from the military authorities. On 22 July, a large-scale roundup began, carried out by Army High Command 14 (Armeeoberkommando 14), affecting the areas of Pian di Setta, Bozzo, Monte Salvaro, Veggio, Ripoli, and parts of Montorio.

Two German columns set out from Pian di Setta, one moving along the Setta valley floor and the other along the ridge toward Tavernola. Many civilians were arrested: some were executed on the spot, others taken to Ponte Locatello. The bodies were left unburied for days as a warning to the population. Parish priest Father Libero Nanni managed to secure the release of some hostages, while about 70 prisoners were deported to Bologna, to the Caserme Rosse barracks and the San Giovanni in Monte prison. The roundup ended with looting and cattle theft. Over four days, a total of 24 civilians and four partisans were killed, including Carlo Rondelli of the “Stella Rossa” brigade.

The Oratory of San Vincenzo Ferrer, a 17th-century building repeatedly renovated, was converted in 1984 into a memorial shrine for the victims of these attacks. A plaque with the names of the fallen is placed on the façade, while other markers in Pian di Setta and Bozzo commemorate the massacre.